Wednesday, December 30, 2009

All the matchpoints

It’s rare for 100% of the matchpoints to be at stake on any decision. Look what happened on this hand. In a robot duplicate I held AJ98 7 A73 KJ532 and opened 1C. It continued 1H by lho, X by partner, up to me. I think this is an obvious 2S bid. 1S is a nothing bid that could be on 3 trumps with no H stopper, so to me 2S shows only something like 14-16 support points, which I have easily. The field disagreed unanimously: 24 of 24 bid 1S! So, when North bid 4S, I was unknowingly in a top or bottom situation, looking at:

North: KQ54 QJT Q6 T764

South: AJ98 7 A73 KJ532

West cashed a heart and led the ST. I played SJ, S8 and he pitched a heart. I opted to overtake and lead a club (I must note I erred by leading the 4 rather than a higher spot, although this turned out not to matter. Never waste your smallest spot from the short hand!) RHO hopped CA to lead a heart; I correctly pitched a diamond and lefty won and played a 3rd heart, RHO ruffing. Now a simple matter to overruff, pull trumps and guess clubs, playing LHO for Qx (which he held) since he would lead a stiff, for making 4 and all the matchpoints. Almost...

See, I use the keyboard input on bbo, which works fine; no typos for some time now. When following, you just hit the rank; when not, suit then rank. *But* if you just hit a rank, it assumes the last suit you played if possible. You see where this is going? By just hitting A, I “overruffed” with the DA instead of the SA! That was down 2, and exactly 0% of the matchpoints. You can see all the results at http://online.bridgebase.com/myhands/hands.php?traveller=2701-1262208601-558614&username=jlw77

Saturday, December 26, 2009

Robot Statistics

Most of you are BBO users, and probably know of the robot duplicate tournaments that were introduced earlier this year. You play against three robots (the program GiB, on one of its faster, less skillful settings) and your scores are matchpointed against other humans playing the same hands. You always get the most hcp at the table. The attraction of this format is that you have many more key decisions per hour than you do in a normal human game; you wind up declaring about 55% of the hands, and the hands go by pretty fast. As a result some people I know are total addicts…I’m a very mild but steady addict, playing 3-4 12-board sessions each week. Of course, the context of some decisions is very different from real bridge, where you wouldn’t (I hope) follow the rule of “never count on partner’s judgment.” You can read a long series of articles on Glen Ashton’s blog and some on Memphis Mojo’s. As far as tactics, I basically open a 14-18 notrump (a bit liberal on distribution) and 19-21 2NT. This is not only to hog the hand, but also because partner’s bidding is not quite as bad as in other auctions.

Partly because it is rare to have useful statistics on individuals in bridge, I got curious about breaking down my results and those of others. Bridgebase will give you a file with a month’s worth of results, and I wrote a parser to break these down by who declared. I might compile more statistics at some point. Here’s what my program outputs now, from being fed the last 3 months of my results (SD=standard deviation):


North declared 105 hands(24.36%): NS averaged 55.22%, SD = 23.15
East declared 41 hands(9.51%): NS averaged 53.77%, SD = 28.04
South declared 243 hands(56.38%): NS averaged 60.55%, SD = 26.31
West declared 37 hands(8.58%): NS averaged 61.80%, SD = 27.91
Pass declared 5 hands(1.16%): NS averaged 50.81%, SD = 10.13
Total of 431 deals, Average: 58.60% SD: 25.93
(Statistics exclude 1 average minuses.)

Comments: It’s not surprising I average better as declarer than as dummy. This doesn’t necessarily mean I should hog it even more – on a hand where I artificially made myself declarer by putting it in an inferior contract, my average would certainly be less than the 60.55% above. In fact, I’m quite satisfied with averaging 55% as dummy – this is a rare instance where we can say for sure that any advantage over the field represents solely bidding judgment! Good players who I’ve looked at tend to average 53-55% as dummy – this partly represents bidding to the right level, and partly that the field sometimes takes hand-hogging to excess. Finally, note that the swingiest hands are when I defend. The field doesn’t like to pass, so defending leads to some tops and bottoms. I defend a few percent more hands than most people I’ve looked at. (One reason is I avoid marginal takeout doubles, fearing partner’s insanity.) The results are acceptable, with a mp average on defense only about 1% less than my overall.

The highest MP average I’ve come across is Mark Lair’s. This could surprise you only if you didn’t know he plays the GiBs quite regularly. Here are his stats for a 2-month period:


North declared 558 hands(30.56%): NS averaged 55.07%, SD = 23.15
East declared 132 hands(7.23%): NS averaged 57.14%, SD = 25.97
South declared 1009 hands(55.26%): NS averaged 62.42%, SD = 24.68
West declared 120 hands(6.57%): NS averaged 55.20%, SD = 27.18
Pass declared 7 hands(0.38%): NS averaged 62.69%, SD = 16.47
Total of 1826 deals, Average: 59.32% SD: 24.72
(Statistics exclude 72 average minuses.)

I can certainly live with being just 0.7% worse than Mark Lair, at this odd but entertaining form of the game.

Monday, November 16, 2009

A better line for today's NYT hand

Many of you are probably regular readers of Phillip Alder's fine column in the New York Times. It's hard to say that someone misplayed when they executed a successful compound squeeze, but I think that is true in today's hand. First look at http://www.nytimes.com/2009/11/16/crosswords/bridge/16card.html?_r=1&ref=arts and see what you think. Then, here is the message I sent to Alder:

Hi Phillip,

It appears that once West pitched a club on the 3rd trump and then turned up with 4 spades, a simple 100% line was available. If declarer, after 3 trumps and 2 spades, just played CA, CK, club ruff, then if West guards clubs there is a simple squeeze (cash last trump then hearts) and if East guards clubs a standard double squeeze with hearts the common suit. In practice, of course, clubs would simply split. The club pitch is vital to this being 100%; it means declarer will always know who guards the last club. Note that Bertheau’s compound squeeze line is not 100%, as declarer can guess wrong as to which suit West has unguarded.

Therefore, the club pitch by West is an error, although understandable since declarer’s hand was completely unknown. To avoid giving declarer a sure-thing line, West must first pitch a heart. A club pitch on the 4th trump would be OK, since any pitch by declarer weakens his hand in a way that kills some variant of my 100% line.

Jonathan

Sunday, November 15, 2009

Establish your tricks -- lead trumps!

When balancing or competing against the opponents' 2S, one thing you fear is that your side has 3 7-card fits to choose from at the 3-level -- usually not a fun choice. But sometimes the opponents let you off the hook.

North: KTxx QJxx xx AKx
West: xxx AKx xxx Q9xx East: Ax xxxx AKxx Jxx
South: QJxx Tx QJxx Txx

At neither vul in a close sectional KO final, North opened 1C and raised partner's 1S to 2S, and East (Marty Harris) entered with a double. I guess (?) that most good players would favor this action at these colors, even though it is far from safe. I (West) bid a scrambling 2NT, preferring this to 3C in case partner is 2=4=5=2 or the like -- I also see a case for 3C, putting the ruffs in the short hand if (as here) we have a choice of 4-3 fits. Seemingly we were headed for -100 in 3D, but North came to the rescue with a 3S bid -- he had told his story sufficiently already, don't you think?

So, my lead against 3S. It seemed unlikely hearts were going anywhere, so I avoided the AK lead and tried a trump. This was a success when Marty won and found the club shift. Now it was routine to take 6 tricks for +100, and win 5 when our teammates played 2S for +110 on the HA lead. It's cute that we must avoid touching either of our AK holdings to get all our tricks, and that my trump lead allows a succesful active defense while the HA blows a tempo! My satisfaction with this is far out of proportion to the 1 extra imp it gained.

Alas, this hand was not enough, and we lost the match by 6.

Wednesday, November 4, 2009

Follow-up to lead problems

1. I didn't find it at the table, but on later consideration I think DA as Pretender suggests is clearly the best shot, trying for a simple path to 4 tricks. It does clear up a guess when partner has Jxx, but so be it. This was the winning lead at the table. Even though declarer had only 3 diamonds (6=3=3=1) and can pitch the third, your trumps are promotable when partner turns up with Jx and the HA.

2. I led the CQ, and clubs were the only losing lead. I still think maybe it was normal, but perhaps there is a good reason to make a different guess. Mojo, why is a heart so obvious?

Monday, October 26, 2009

Decisive opening leads from Sunday

I hope some loyal readers have their alerts set to find out there is an actual post! I'm busier with work this year, so the blog has slowed way down. I did make it to a regional in Lake Geneva, WI this weekend. Here are two critical opening lead problems from yesterday's Swiss:

1. You hold AT Jxxx Ax QTxxx, and the opponents bid uncontested, P-1S-2C!-2D-3D-4S, where 2C was defined as 3-or-4-card Drury, and 2D as natural. What do you lead against 4S?

2. You hold xxx QTx 9x QJxxx, and they bid uncontested 4S-4NT-5H-6S. Your lead against 6S?

Saturday, September 12, 2009

Defensive problem from BB final

You're up about 80 with 42 boards to go in the Bermuda Bowl final, and your opponents aren't shy to begin with, so you'll be given some defensive opportunities. Here's a chance to pad your lead...or make things a little more interesting:

You: T7 K32 QT73 AK84 Dummy: A984 T876 A J653

You deal at both vul., and it goes 1D-P-1H-1S-X-3D-X-P-P-4S-AP. I'm pretty sure 3D was a 4-card limit raise and passing 3D-X showed interest.

You lead the CA (agree?) and get the CT from partner, right-side-up. Your move?

Tuesday, September 8, 2009

Play problem from Monday's Swiss

The obvious 1nt-3nt auction gets you to a contract that is tenuous, to say the least:

Dummy: 94 Q94 AK764 T92
Declarer: Q763 AJ83 J53 AK

West leads the C4. Plan the play (at imps).

Saturday, August 29, 2009

A bit of a break

I've been taking about a month off from playing bridge for the first time in more than a year. It's interesting, it actually takes a couple of weeks for decompression before "bridge thoughts" stop going through my mind at random moments. Anyway, after I move back to Evanston on September 1, I'm playing several days at the sectional in Skokie September 4-6, so I should have plenty of new material then! I must admit, I like writing about bridge about as much as playing it.

Tuesday, August 11, 2009

6-6 hand follow-up

Maybe this isn’t a good problem, since everyone is bidding like me. To make it a discussion, I’ll make the case for passing: partner is still there and has heard you imply a good deal of shape (though not necessarily 6-6.) He is marked with length in hearts, and if he has strength there also it could be right to defend; with weak hearts maybe he’ll find another bid. Well, ok, this doesn’t convince me pass is right…partner had some reason to come alive with 5S, and you know it wasn’t his diamond holding! So here’s the story:

At the table I bid 6S without much thought, beyond that partner could have Axx or Axxx in trumps and have not thought his hand was worth 3S the first time, and that 1430 is a lot more than 100 or 300, not to mention -200 being better than -920 or -1090! Tempo probably wasn’t that crucial, but it felt like the kind of situation where I shouldn’t betray doubt, because there is an excellent chance the opponents will save; of course, maybe I want that and maybe not, who knows? Well, unfortunately partner had Jxx AKxxx xxx xx and I’m sure was hoping to double 6C. Even so, the whole operation could have worked if the opponents had saved, as they might on many layouts. They can't know that I'm void in hearts and not clubs. But alas, lefty had AQx QJxxx --- AJxxx and that was an easy double. The “good news” was that he led the CA for down 2 rather than underleading for a ruff and 800 J. The other “good news” was that our teammates had scored -620, selling to 4S after not finding clubs, meaning that -500 was only 4 imps worse than +100. The non-ironic good news was that we had good cards at both tables otherwise, and after expertly “crashing” these bad results for -15 we won the match by 11.

Sunday, August 9, 2009

An appealing hand (no pun this time)

Here’s a bidding problem that came up in the Open Swiss. I thought my tempo was a potential issue – for the information it might give the opponents as well as the UI it might give partner -- so you might want to take the following approach: first decide in 5-10 seconds what you would do if you think it’s important to bid in tempo, then consider if you might revise your action given unlimited time. That’s how we ultimately progress towards making the right bid at the table, in tempo, right? I’ll post my thoughts and the story later.

You pick up KT9xxx ---- AKQJxx x (not bad) and are dealer, red/white, so you open 1S. Lefty (Dan Morse) bids 2S, partner passes, and righty (Nagy Kamel) bids 4C (pass or correct). Let’s assume you bid 4D – then lefty bids 5C, partner chimes in with 5S, and righty bids 6C. Your move?

Monday, August 3, 2009

An "appeal"ing hand

(Updated 8/04: When my teammates told us this story after the game I misunderstood who was sitting where. The version below is correct.)

Both red, playing in the final round of the national swiss against Fantoni/Nunes, with a range of final placings from about 10th to 40th still possible, you hold Qx A AT9xx AQJxx, and RHO deals and opens 1H. Probably you are thinking you would bid 2NT...do you have a second choice? My teammate Hailong Ao had a different first choice -- he bid 1NT! I won't debate the merits of that, but it did get his high-card points off his chest :-). Now lefty bids 3H, explained as "weak but not crazy," partner passes and righty bids 4H. If you had to sit in at this point, would you act again? Consider for a moment before reading on...





Having shown his hcp but not his shape (to say the least) Hailong continued with 4NT! Although it looks very odd on the face of things to commit to the 5-level on your own, I actually think this is definitely the right action here. RHO must have a distributional hand to justify 4H, and his most likely shortness is in clubs, because if he had club length it would be weak length with the K badly positioned. Hailong's partner, JJ Wang, must have been very surprised to hear 4NT, but quite pleasantly so, for he held xxx Jxx x Kxxxxx, and as you can see 5C rolls. Furthermore, the opponents couldn't resist doubling, so that was +750.

But wait! Over 3H, which the opponents alerted (not alertable for a few years now, but most people seem not to know that,) JJ had inquired and been told the meaning. He then passed in tempo, but nonetheless the Italians felt that UI had been conveyed and this had influenced Hailong's 4NT bid. What do you think about their case?

I don't think they had a case. Some people will always inquire about an alert in a competitive auction -- it is certainly more common to ask only sometimes, but this is clearly an inferior practice and conveys more UI. JJ's hand, which couldn't possibly act over 3H, suggests that he was just asking reflexively and it meant nothing. Maybe he was surprised to hear an alert because he knows 3H is not alertable! He also might have been surprised to hold 3 hearts on the auction and thereby been more curious about the 3H bid, but if his question only conveyed that, it would hardly be an impetus for Hailong to bid. Well anyway, the director ruled that the result was rolled back to 4H making (it is down on optimal defense, but in these cases you don't assume that.) But late at night, the hardworking commitee restored the table result, +750 for our teammates. I look forward to the write-up in the appeals casebook.

At my table, I held opener's hand, KJx KQTxx KQJxx ----, and the auction was a pedestrian 1H-2NT-3H-5C-AP, so we scored -600. We missed a decent save in 5H (down 2, probably), but I really don't feel I should be bidding it on my hand -- partner hasn't even promised 4 trumps. So the appeal swung 19 imps, from -15 to +4...it also swung the match from -10 to +9, and our final ranking from 29th to 14th. The final match, which was the only one we played with computer-generated hands, was plenty interesting -- the final score was 30-21. Half of our imps came when we got pushed to 6C doubled, red/white, with about half the deck and a 12-card fit...it turned out to be on a hook, which won, for 1540. They got to 6C at the other table also, but our teammates took the save in their 11-card heart fit for -300.

Monday, July 27, 2009

Card combinations you're surprised not to know

Or at least, I was surprised not to know.

Consider the following combinations:

A: AQ983 in hand opposite 542
B: AJ82 in hand opposite K543

and assume you are maximizing average tricks, with no entry restrictions.

Alan Applebaum was asking a bunch of people on Friday, just before the LM pairs started, about A. Almost everyone (including some top players) played low to the 8, then if that lost planned to hook the Q the second time. This is actually wrong, because it only gains when lho has JT doubleton and loses when he has stiff “jen,” compared to hooking the 9 the second round – it’s a restricted choice position, but one that seems to have gone unnoticed by almost everyone.

Then later that day at the table, position B came up, which happens to be a very close cousin. Our opponent cashed the K, and when the T appeared on the left hooked the J, commenting that she wasn’t sure that was right. Actually it’s right to hook the 8 (or cover righty’s 9 cheaply) on the second round, for similar reasons. You win against stiff T ( or 9), lose to doubleton T9; by restricted choice the stiff “tine” is more likely. At the table, only the third-best approach of going up ace worked; lefty had QT tight. I bet many good players would briefly consider going up ace, then hook the J because they know going up is too susceptible to falsecarding…but wouldn’t even consider the best option of hooking the 8! All I can tell from the recap sheet is that about 25% of the field dropped the Q; no idea how many hooked the J versus the 8.

By the way, there was another consideration on this hand: About 25%** of the field got to the optimal 6nt while the rest, as did my opponents, bid to 6h with this as the trump suit and no other losers anywhere. I’m ignoring the very few who went minus in a grand. Those in the inferior 6H would be justified in taking an anti-field approach in the play, which rates to gain about 70% of the mps when right but lose only about 30% when wrong. I can’t say for sure if the J or 8 is anti-field, but I do know the A is! Disappointingly, a glance at the recap seems to show no correlation between the contract and the number of tricks taken -- those who went +1020 should be a bit ashamed, as 990 was already a good score!

** Update, 7/30: I actually counted frequencies of the scores, see comments.

Saturday, July 18, 2009

Spillover from the Daily Trout

My friend FMB has started a blog called "The Daily Trout" with some very nice hands in the first week, linked on the right. If he keeps up the Daily I'll be extremely impressed. His recent posts beginning with "Names withheld to protect the innocent" had a hand that, first off, is a cool bridge story (featured in a book on Helgemo), and also brought up some really nice game theory. I had so much to say I'm continuing the discussion here. Check out the hand at his site first, then continue here if interested. This is intended to be accessible to anyone with a passing knowledge of equilibrium in game theory, on the level occasionally found in The Bridge World; I hope it doesn't get too dense.


It was with a bit of guilt that I wrote my first comment, which I knew only gave the solution assuming average-trick maximization when BAM play might be different. I knew the BAM analysis would be more complex and wasn’t sure anyone would care, but I am very glad FMB did care, because now that he got me to think about it more, this is a great hand from a theory point of view! As he points out, this is really a 4-player game: let’s call the players S1,E1 (team 1) and S2,E2 (team 2). Each South can plan to go up (U) or duck (D) when East keeps a club, and each East can bare (B) or not bare (N) the K when he has it. There are 3 distinct ways to look at equilibrium in this game:

I) Correlated team equilibrium

Each team picks an overall strategy which can be any mixture of the 4 pairs of South and East strategies, UB, UN, DB and DN. It’s an equilibrium if the other team has no better-than-even response.

This becomes in effect a two-“player” symmetric zero-sum game, thinking of each team as a player. I had to turn to Matlab to invert the 4x4 payoff matrix, and eventually found that the unique equilibrium was .5 UN, .25 DB, .25 DN. Notice that:

a) The percentage of B by the Easts (.25) and U by the Souths (.5) is the same as in the average-trick maximization analysis that looked at just one table.
b) S1 and E1, also S2 and E2, must correlate their strategies to never play UB. This may or may not be possible, but leave that aside for the moment.
c) No one ever wins the board by two tricks, because this would require both teams to play B with one D and one U, not possible if no team ever plays UB. This is why the average-trick equilibrium translates into a BAM equilibrium here – when the trick difference is always -1, 0 or 1 it gets converted linearly to the BAM scale.
d) Comment c provides some intuition for why UB is avoided; a team that plays UB would be in “danger” of winning the board by two tricks, which wastes some of their average trick total. Even more intuitively, if your teammate South is playing Up, there is some chance as East that you have already won the board by not baring, so baring could be pointlessly risking a valuable trick for a valueless one.

II) Independent team equilibrium. Each team announces their randomization which must consist of *independent* randomizations by S and E. It's an equilibrium if the other team has no better-than-even response.

Fascinating to me is that there is no type II equilibrium! If you believe me that the equilibrium in I is unique for its type, this is actually pretty immediate. A team has a better-than-even response to any randomization that isn’t the correlated one in I, which implies that one of the four pure strategies must be a winning response, and pure strategies of course satisfy independence.

How is this possible? Doesn’t it violate Nash’s Existence Theorem? No. Why? When Nash’s Theorem is applied to games of more than two players, you have to be careful about the definition of equilibrium. A 4-tuple of strategies is a Nash equilibrium if no *single* player can improve his outcome by deviating. Nash doesn’t recognize teams, so his theorem doesn’t apply to the equilibrium concept defined above (II), which says equilibrium can be broken by two players deviating together. Nevertheless concept II is fairly natural, and there is something disturbing about the fact that there is no such equilibrium. Think about it: If S1 and E1 huddle and decide on a randomization for each, then *whatever* they decided, team 2 has a winning response if they just know the frequencies. This is totally opposed to the usual intuition for mixed-strategy equilibrium.

III) 4-player independent Nash equilibrium. Each player announces a randomization – again, teams cannot correlate. It's an equilibrium if no player can improve his lot by changing his plan, with both his opponents *and* his teammate held fixed.

Nash tells us that such a thing definitely exists. FMB must have been referring to this type when he said East should bare 1-sqrt(.5) of the time. I haven’t been able to verify his calculations yet; I get some equations that are a bit hairy when I try to solve for the type III equilibrium.

All of this brings up the issues: Can teams correlate? Is it legal for them to correlate? I’ll comment on that sometime later, but for now will note that being able to correlate seems to provide some edge, although it is difficult to define how much: the two-team game where one team can correlate and the other must be independent has no equilibrium! Frankly, I find the conditions in II more natural bridgewise than I or III, but that's the one that leads to non-existence!

Saturday, July 11, 2009

Ruffing squeeze without the count

Update: I decided to try out the BBO handviewer program -- thanks to Memphis Mojo for recommendation and advice, and to Fred Gitelman for the program. So, anyway, you can see the whole deal in much prettier format at the bottom of the post -- but may want to read the story first.


On Thursday, the A/X Swiss played 7 8-board matches, while the lower brackets played 7 X 7. The thing was, the directors put us all on the same clock (I think 40 minutes to start the last board.) Yikes, this wasn’t billed as the Speedball Swiss! Anyway, the constant time pressure figures a bit into this story, also from the 5th match:

Dummy:...KT4....J874...A85 QJ5

Declarer:AQJ953.KQT6...T94 ---

I was dealer, neither vul, and the competitive auction went

1S-2NT-3D!-5C

5H--P--5S--AP

3D showed a limit raise+ in spades.

Lefty led the HA (I played the T) and shifted to a club – J, A, ruff. By isolating the club menace against himself, he had given me a chance. I considered the possibilities:

A simple squeeze? This would require ducking a diamond to rectify the count, and the defense wouldn’t have to be especially brilliant to continue diamonds, leaving no entries – the end.

Ok, it would have to be a squeeze without the count. The conditions weren’t right for an ordinary one (control of both suits) – what about a ruffing squeeze without the count? Cash all the trumps but one, then hearts ending in dummy. That leaves Ax Qx in dummy and three diamonds and a trump in hand, and if lefty keeps Kx clubs he has only 2 diamonds, and you can establish the last one in hand…that works! Nice – the kind of hand that makes your day.

Dear Reader, I did work all this out before trick 3, and I did make the contract…I wish I could leave it at that, but journalistic ethics forbid. Recall that we were under time pressure; having taken several minutes to plan the play, I started to play fast once I knew the solution. I pulled 3 trumps (lefty had one), and then, somehow…a small heart came out of my hand. As it hit the table, I realized with horror I had wrecked my perfect ruffing-squeeze-without-the-count, because I could no longer cash hearts ending in dummy as was required. Bob may have seen me shake my head at this point and wondered why. Was there still hope? Yes! Go back to Plan A: If, as wasn’t extremely unlikely, righty had any stiff diamond honor, I could rectify the count for a simple squeeze, and it couldn’t be broken up. I finished the hearts (optional). These cards remained:

--- --- A8x Qx

xx --- T9x ---

I played a diamond to the 8 and K. Righty perforce played a club, ruffed, and I knew a simple squeeze was inevitable. Actually lefty had bared his CK earlier so it appeared now, but that didn’t matter. A less-than-completely-triumphant making 5. At least shifting to the simple squeeze had meant no count guess in the ending! Lefty started with x A QJxxxx Kxxxx.



The whole deal in bridgeviewer, some low spots approximate:




At the other table, Bobby Levin for once fell from grace and duplicated the defense at the first two tricks (HA, club) – hard to envision this layout, I guess.
RJ did say he signaled for diamonds. But the opposing declarer fell at the first small hurdle and didn’t play a club honor from dummy! RJ could play the T and there was no chance of a squeeze – 11 to the good guys.

Friday, July 10, 2009

Nice defense from regional Swiss

Between the trials in June and nationals in July, and the fact that I’m only living in Princeton for two more months until I have to go back to Evanston and leave my wife here for the year, I’m not playing many sectionals or regionals this summer. I did make it to the Philadelphia-area regional for one day yesterday, to play the Thursday Swiss with Bob Heitzman and RJ Becker-Bobby Levin. The great thing about bridge is that there are as many interesting hands in a Thursday Swiss as in a world championship. After 4 of 7 8-board matches, we had 60 and played the leaders who had 61. We won two game swings and a partscore swing that featured interesting play and defense, for a blitz, then blitzed again in round 6 and actually clinched with one to go. Here’s the first game swing:

Dummy: .Axx...xx.....AQTxxx..xx

Declarer: Qxx...KQTxx...K.....KJxx

I arrived in 3NT with lefty overcalling in spades: 1H-(1S)-2D-2NT-3NT

ST (rusinow) was led to my Q. I could make if diamonds came in, with maybe some additional chances. I cashed the DK and led the HK. Lefty won and continued spades; I won (ducking would have been fatal) and righty pitched a club. I tested diamonds, keeping all my hearts, but righty turned up with Jxxx. Time to try hearts; I hooked the T which held and played two more rounds, righty turning up with Jxxx in that suit also. Righty tried a low club and I had no guess; I had to try the CK and it held, so my last heart made nine tricks. Lefty’s hand was KJTxxx Ax xx Qxx. It always feels good to make a thin game with less-than-perfect breaks, but it didn’t feel as if I had done anything special or the opponents anything silly. It’s a hand where you hope for a swing but aren’t sure. There was a swing, because the defense *had* slipped, as Levin demonstrated at the other table. Do you see where?

After the first two tricks were the same (spade to Q, DK), Levin ducked the HK! This completely wrecks the entries, and declarer cannot make it even with mirrors. In fact, he went down 3. I think that for many players the duck would not be instinctive, but on a bit of thought, it almost can’t be wrong. The DK really looks like a singleton. If declarer has Qxx KQJxx Kx Jxx (so you need to win and cash clubs), he has made an implausibly subtle double-cross play by cashing the DK. With diamonds running, almost any declarer would either try to slip a heart by without cashing the DK, or run the whole diamond suit hoping for discard trouble. I am sure that Bobby’s instincts told him that diamonds weren’t running, (or at least that he should play for that), and he found the duck without much effort.

I’ll try to post the other hand, a cute squeeze hand, tomorrow.

Thursday, July 2, 2009

Sequel: Play it better than GIB

After the auction begins as in the previous post, you arrive in 4S with:

Dummy: A75 J93 K843 KT8

Declarer: KJ643 A62 AJ2 93

This is not one of the ideal combinations you were hoping for, but you still have play. The early play goes:

CQ, K, A, 3

Club, 9, J, 8

Heart, 9, Q, A

S3, 2, A, 9

CT, small, H2, small

S5, T, J, Q (sigh)

S8, 7, club, K (new life?)

Yes, there were some layouts where a diamond hook at trick 6 is better, but if trumps come in you’re probably making it without the D hook, so playing trumps looks right. Your bidding convinced lefty you were 5-2-4-2, so he didn’t cash the setting trick with HK (wrong of him, since on that layout the pitch he set up would be useless.) Now, here you are needing the rest with:

Dummy: --- J3 K843 ---

Declarer: 64 6 AJ2 ---

Any chance?

Most of you know that GIB’s algorithm for single-dummy play is to generate lots of random hands, then see how to make it double-dummy. It thus tends to miss plays that “steal” tricks in single-dummy play. Here, like a good GIB, I calculated that the only legitimate chance was for rho to have T9 tight in diamonds. Then I have 9 tricks with the backward finesse, and LHO with his presumed HK is squeezed out of his Q76x in diamonds for 10. So, I cashed my trumps pitching hearts; unfortunately no diamonds were pitched, so it was clear there had been no squeeze. Knowing it was unmakeable, I just played DK, diamond hook to try for down 1.

Did you see the play that, GIBlike, I missed? Just lead the DJ from hand. If lho has Qxx (no T), you’ll make it for sure – no way will he cover when he thinks you have AJTx and are trying to tempt him. This also retains the tiny legitimate squeeze chance I mentioned.

In practice lho had Q and T of diamonds, so nothing works, except stopping in 2 or 3 spades!

Simple Drury decision

In 4th seat, white at imps, you open 1S with KJxxx Axx AJx xx. Opponents pass while partner bids 2H, artificial, your version of 3-card Drury. Your move?

Maybe a 13-count opposite a passed hand doesn't sound too inspiring...but this hand meshes very well with some 3-card limit raises. AQx xxx KQxx xxx, for instance, produces a near-cold game, as does AQx KQxx xx xxxx, or similar hands with the SA in a different suit. Some combinations, obviously, aren't nearly as good (some club holdings will be wastepaper), but when multiple combinations can make it near-cold I felt compelled to make a try. 3D is a naturalish try and I bid that. What does everyone else think?

Wednesday, July 1, 2009

Richard Freeman

passed away two days ago. I played a 16-board set against Freeman(+Nickell) a few years ago and thought he was as sharp an analyst as I've ever played. He played on championship teams in just about every era of bridge. In my opinion, Freeman was an underrated part of the Nickell machine who will be hard to replace.

Tuesday, June 30, 2009

A straightforward (?) 6nt

I was kibitzing on bbo vugraph when declarer had to play this hand in 6nt:

Dummy: xx KQT9 AKxx AKJ

Declarer: KTx AJx Qxx Q9xx

A heart was led.

Apologies for the length of this analysis; as in my favorite Twain quote, “I didn’t have time to write a shorter one."

The obvious question is, do you (a) play a spade to K without testing diamonds, or (b) test diamonds first? As a straight percentage problem, the easiest thing to calculate, I think, is swing cases. (a) wins a swing when rho has 4 diamonds and SA, about 11%. (b) wins a swing when diamonds 3-3 and sa off, about 18%. Note that when diamonds are 5-1 you can switch to spades, so no swing in that case.

We didn’t take into account that an expert lho may duck the SA (!) when you lead low to the K (if you do it early), hoping you have KQT and misguess later. The likelihood of this is very hard to evaluate.

Of course, it looks attractive to (c) cash your hearts+clubs before committing yourself. The percentages may change. You would come down to:

Dummy: x --- AKxx ---

Declarer: KT --- Qxx ----

and can still choose either option. The drawback to this is that when LHO shows out on the second round of diamonds, you can no longer switch gears (you’re cut off from spades,) so this line looks bad when diamonds are 5-1. You might therefore leave the 4th club uncashed. But cashing all your winners has an advantage: if RHO started with QJxx spades and 4 diamonds, he’ll be squeezed down to a stiff spade honor and you make it if you read the position, which I think you will: who is diabolical enough to pitch a spade honor and keep 2 small, holding such as Jxxxx xx Jxx xxx?

I love how this extremely simple-looking hand has so many wrinkles. Another diabolical falsecard opportunity that might occur is when RHO has the aforementioned QJxx xx JTxx xxx. When you cash hearts and clubs, what if he nonchalantly pitched a diamond and two spades (preferably diamond first,) unguarding diamonds? Wouldn’t you think he must have started with 5 diamonds, and play for the SA onside? Could any defender do that in real life, though? He doesn’t even know you have the ST.

My verdict is that I would cash all the winners (this is assuming hearts+clubs aren’t 5-1), then try to get the ending right – if RHO has even two fewer round cards than LHO, my calculations say the percentages shift enough to favor (a).

The real-life story? RHO had AJxx xx JTxx xxx. Both declarers tested hearts and clubs without cashing the 4th club, then despite the breaks took line (b), going down for a push. If they had cashed the last club they would have seen the SJ pitch and probably gone right whether or not they did the math. No falsecard opportunities with this hand; any other pitch leaves declarer only winning options.



Friday, June 26, 2009

No inference from the auction?

White on red, you deal and reach 4H on an uncontested auction: 1H – 4C - 4H

Dummy: 984 K952 A87643 ---

Declarer: A2 Q8764 QT92 A6

There is no perfect bid with dummy’s hand, so I think the splinter with a void is fine. The SJ is led. How do you play?

With this trump combination, you need to decide which opponent is more likely to have a stiff trump and lead a low one through him, succeeding when he has stiff A, J or T, as well as on 2-2 breaks other than JT tight (assuming you take the second-round restricted-choice finesse.) No opposing bidding here, so it’s just a guess, right? Not at all! It was much easier for lefty to enter this auction than righty, which means that righty is much more likely to have a stiff heart (and 10 or 11 black cards.) So, ruff a club and lead a small heart. I’ve thought about this kind of auction before, so the inference should have been routine, but somehow when it came up (round of 32 at the USBC) I was “off my game” and played a heart to the K at trick 2. RHO had stiff T, and there was no stiff K in diamonds, so that was down 1. I cannot report the auction at the other table, but the board was a push.

Note that because the auction makes 2-2 trump breaks more likely, one might be tempted to go against restricted choice even when the HT appears, but I do think you should finesse…there are lots of hands where rho can’t bid red/white with a stiff heart.

The hand record is at http://usbf.org/docs/vugraphs/USBC2009/hands/USBC2009_R32_13_20_1-30.PDF (board 12)

A digression on tennis

I'm generally interested in the rules of all games -- in particular, in the "best" set of rules, that will make the game the most fun to watch or play, or most likely to pick a worthy champion, according to the goals of the contest. Those of you who have watched Wimbledon over the years won't be surprised by what I have to say: the game (on the men's side) would be much more fun to watch if the serving weren't so dominant. I (and others) have thought this for years; I was reminded by having just viewed what is probably the most extreme set ever played in this regard. In the 4th set between Ivo Karlovic and Jo-Wilfried Tsonga, they reached 6-all with the servers losing only one point combined! That's 24/24 for Karlovic, 24/25 for the comparatively pathetic serve of Tsonga. They must have choked up under the pressure of the tiebreak, because the 6'10" Karlovic actually lost a point on serve (by missing an easy volley) and Tsonga lost two, Karlovic taking the tiebreak and the match 7-5. Too bad, it would have been fascinating to see how long the 5th set (with no tiebreak) would have lasted! (Note: Just before I tuned in, Karlovic had in fact won the 3rd set with the only break of the match.)

Well, it's clear the game would have more suspenseful moments for the fans, as well as putting more of a premium on a variety of skilled shotmaking by the players, if the serve weren't so dominant. Of course if someone wanted to fix this, it's not hard to think of proposals such as shrinking the service box or, even more extreme, allowing only one serve. There are reasons, of course, that this is very unlikely to happen. For one thing, the current top players have mastered their craft under the current rules, and I suspect they would hate the idea of any significant change. For another, the current rules work fine for casual players, and it would be inconvenient to have different rules at all levels other than professional (I admit that even as a *very* casual player, I liked the idea that I was on the same-shaped court with the same rules as the pros.)

Something that can be done without a revolt is to tinker with the surface, and in fact Wimbledon did this a few years ago, so a backcourt game is more viable there than it used to be, and returners have more of a chance. I find the improvement in watchability to be generally quite noticeable. Also possible is some restriction on rackets -- I've heard this is politically very difficult because of the sponsors, but golf restricts the clubs, so maybe it's not impossible.

By the way: a very modest rule change that players might not find too jarring would be to make all serves that hit the netcord faults (as in volleyball.) No one aims for the netcord, and it's basically luck when it drops in for a let anyway, so this leaves the game relatively unchanged while decreasing the server's advantage by a smidgen.

Friday, June 12, 2009

Squeeze or be squeezed

A simple-looking 3nt on board 32 from our 3rd quarter against the Diamond team led to very interesting play. The hand record is at: http://usbf.org/docs/vugraphs/USBCUSA2/hands/USBCUSA2_2009_R32_5_T1_31-60.PDF

The play started the same way at both tables: North (Brad Moss and I) led a spade, declarer played 2 more rounds, and we played a 4th round. Now declarer led the DQ and we both erred by ducking. Brian Platnick capitalized by cashing his clubs, and I was squeeze/endplayed – whatever I pitched, he could exit appropriately for 9 tricks. Note the difference if I win the diamond and cash my spade -- *declarer* is squeezed from 9 winners down to 8, I exit safely, and he is down. Notice also, declarer had to “steal” that diamond trick before the squeeze would function against me. Well played, right? Maybe not.

At the other table, after the DQ was ducked, declarer (Mark Lair) led a heart to the K, for an immediate down 1. The commentators found this odd, but unsurprisingly Lair’s play is well-reasoned. Suppose we move the HA to the South hand. Now after Platnick cashed his clubs and exited a diamond, the last spade would squeeze him for down 1. (The defense has cleverly lost 8 tricks to rectify the count J.) So effectively Platnick played North for the HA and Lair played South for it -- Lair’s play looks like the better percentage because of the spade distribution, so declarer “should” go down even after the misdefense. Maybe Platnick thought he had a sure thing by forcing me to lead hearts, and overlooked the possible impending squeeze against him. Or maybe I do him a disservice and he “read” me for the HA, but I don’t see how.

Now, Moss and I should have been able to avoid that fatal diamond duck – once you think about it, it can’t be wrong to win, cash your spade and exit. We were led astray by the rule of thumb “no point in winning the trick if you don’t have 5 to cash.” This is often a good rule, but the rule that truly applied here was “grab your tricks early if endplays are possible.” Note that this would have been really obvious if clubs had been cashed first, and we had pitched a diamond – no one would then duck the diamond and leave themselves with bare ace. Holding Axx in diamonds gave a false sense that it was ok to duck the trick – the third diamond is an illusion because you can be squeezed out of it.

By the way, it looks like an improvement for declarer to play one round of diamonds before the 3rd round of spades. This is necessary to make it double-dummy (following Platnick’s line thereafter. If you plan to play South for HA I suppose it doesn’t matter.)

Sunday, June 7, 2009

In Round of 16

Teammates had great 3rd quarter to lead by 51, we played solid 4th to win by 73.

Now we play against Jacobs.

Saturday, June 6, 2009

Playing the round of 32

Down 12 after 1 quarter. I messed up a couple of hands that are bothering me. Sitting out the 2nd quarter now -- 3rd and 4th quarter tomorrow.

Update: Teammates picked some up, we're up 11 after 30/60 boards. 3rd and 4th quarters tomorrow.

Friday, June 5, 2009

First day complete

Having played 7/10 of our matches, we are 18 VPs above average, 2nd in our group. The first day's results are at http://usbf.org/docs/vugraphs/USBC2009/RRsheet.php?stage=RR1&group=Mets

Cohler, the top-seeded team in this stage (higher-ranked teams have byes), is currently below the surface and has only two matches to come up for air. Schwartz, #2 in our group, has their head just above water. Unlikely they both make it; someone would need to fall hard. In the other group the top teams are much more comfortable. (I prefer the drowning metaphor to an NCAAish "on the bubble" -- maybe it seems more appropriate because we know where the "surface" is.)

Live blog from Team Trials

You hold xxx xx Axx QJT8x. You deal, red/white, it goes P-3D-X-P-?

Let’s say you bid 3NT. It goes P, P, double and you…?

I got this one wrong and we lost that match, but so far about 8 VPS above average through 4 matches.


Update: We’ve now played 6 of our 10 matches and are 20 VPs above average. 7 out of 11 qualify, so we would have to really stink to blow it. We might win our group, which would give us a small bonus in seeding points.

A tricky defensive problem: You hold xxx AKJ9 xxx xxx, on lead against 1c-1h-2nt-3nt. Say you lead the A, which asks for attitude. Dummy has JTx 8xxx Jt9x Ax. Partner plays the lowest outstanding spot, upside-down attitude. Your play?

Tuesday, May 26, 2009

Cute defensive hand

 

This hand is adapted from a Swiss event last week at the NYC regional.

 Dummy:     QT8x  xx   AKJx  Jxx

You:  9xx  AKT  xx K9xxx

 

The opponents reach 4S via a Stayman auction:  1NT-2C-2H-3NT-4S.  You choose to lead a diamond.  Dummy wins, partner encourages.  A heart is ducked to your T and you play another diamond – after some thought declarer, an expert, wins and ducks another heart.  You get out with a third heart, ruffed in dummy.  Declarer runs the CJ to your K and you exit a club which he wins with the A.  Now he leads the HQ.  You are down to 9xx ---  ---  xxx and dummy now has QTx  ---  Jx   x.   What is going on, and what do you do?

 

Answer: Declarer must have started with AKxx  Qxxx  xx  AQx.  So, he could pull trumps and claim, but he is afraid you have 4 trumps (especially since he infers you have only 3 hearts and 2 diamonds) and hoping to get some information when he leads the HQ.  Discard, and he may assume you didn’t want to ruff from Jxxx and hook the ST, going down in a “cold” contract.

 

At the table, I actually had J9x of trumps (that’s the “adapted” part of the story), so there was no way for declarer (Gavin Wolpert) to go down at this point.  He did say he was indeed planning to hook the trumps if I discarded.

Tuesday, May 19, 2009

GNT district final -- slam hand

On Saturday our team (me/Jiang Gu, Josh Sher/Mike Prahin) lost the 56-board District 3 GNT final by about 20 imps.  Good luck to Bob Heitzman/Jeff Aker and Bruce Rogoff/Josh Parker at nationals.  We picked up some imps on the following hand:

 

I held Txx AK  AQx  Kxxxx, partner opened 1H, and the auction was uncontested:

 

1H-2C-2D-2H-3H-4C-4D-??

 

Fortunately we had agreed that 2H here only shows 2.  I think this is a useful bid to have for hands where other bids are misdirected, and I think jumping to 3H over 2D when you want to show 3 and set trumps is fine – still plenty of room to cuebid.  Anyway in our cuebidding style 4C should deny any (1st or 2nd-round) spade control, so I was sure partner had one to make another try with 4D.  I had terrific red-suit cards I hadn’t really promised, so I was sure we belonged in slam.  I decided to bid 6D; it seemed clear this would show 2-3 in the reds and let partner make an intelligent choice.  After some thought, he passed with:  A  J9xxxx KJTx Ax.  There is not much to choose between 6D and 6H, both good contracts; 6D might survive 4-1 hearts if they don’t lead trumps, so it looks a little better, but it could be in trouble if diamonds are 5-1 with hearts 3-2.  Of course at the 7-level, diamonds would be much better – 7D is about 60%, but on this kind of combination can you really be sure your counterparts will reach 6?  They didn’t in this case.  Also 60% is just barely high enough even if we are sure they bid 6; and it’s quite hard for either of us to know enough to give us that 60% -- the DT is crucial, for instance.  So in practice it's a bit academic that 7D is a "good" contract.

At the table, the hearts were Qx and diamonds broke normally, so you’re making 7 of anything – we picked up 12 imps.

Sunday, May 10, 2009

Overruffs looming (Updated)

Here’s a hand from a Thursday match on BBO I worried for a few days I should have played a bit differently:


Dummy:  932   986  AJ9732   4

Declarer: AQT75  AQ5  Q  AT53

 

At both vul, I dealt and the auction was 1S-2C-2S-P-4S-P-P-P

 

The play began unobjectionably, I think:  CK to the ace, DQ to the K and A, heart to the Q and K, HT to the A, club ruff low (rho played the J), DJ pitching a heart (they follow small).  Now the position is:

 

Dummy:  93              9     9732    --

Declarer:  AQT75    ----   -----    T5

 

And you’ve lost one trick.  Your move?

 

(I suppose I should cash the DJ earlier in case clubs were 7-1 and I never get back to dummy.  But we would get to this same crossroads.)  

Update: After a little more thought, I really don’t think my play was wrong.  Anyway, here is what happened:  I realized that the contract was unmakeable if lefty had Kx in trumps (must lose overruff, trump king and club or the equivalent.)  Since I need rho to have the SK, and I can score at most one club ruff anyway, it looked right to play a spade to the Q at this point rather than guess if a red-suit ruff was safe, and that is what I did.  Indeed this line makes easily if lefty has xx in trump, or stiff J.  I didn’t notice until later that you won’t make if lefty has Jx trumps, because there is always a promotion – but no other play will make either, so my original logic and intuition still seem sound.  You also can’t make on any line if lho has small stiff.

 

  So what happened at the table?  Why, the one case I didn’t mention, of course:  lho had stiff K.  So I was down 1.  Of course you can cater to stiff K if you choose; but I don’t see any line which caters to both stiff K and xx on the left – xx is 3 cases, so must be more likely than stiff K even though the individual cases are less likely because of the club break.  Except that stiff K happened – that makes it more likely J.

 

At the other table, there was an interesting variation.  Declarer in the same ending ruffed a heart small which lived, then ruffed a club with S9, overruffed by J.  A trump came back and he had to guess; he finessed, playing lefty for 8x, so that was a push.  I think he actually should have played for the drop at this point.  Suppose lho indeed started with 8x  Kxx  Kx KQxxxx.   RHO has just given you an unlikely gift by playing a trump – if he played the DT, partner’s 8 is eventually promoted (or declarer can pull trump and lose 3 tricks anyway.)  So, going back to the 7-card ending, my play must be right – it caters to all cases of xx (meaning 86, 84 and 64) on the left rather than basically committing you to play for stiff K (or 64) as well as risking 5-2 hearts.


Phew!  After a few days of worrying about this hand, I think my conscience is clean.  Now someone can tell me I’m wrong.