Thursday, November 11, 2010
Check out Bridge Winners
Tuesday, September 28, 2010
Robot madness
Wednesday, August 11, 2010
Bidding Problem
Here’s an interesting hand to bid from the Spingold. I had a promising collection in 1st seat white/red, AKQxxx Kxxxx x x, which got better when partner responded with Jacoby 2nt. What is your plan? Assume standard Jacoby where 4x=5-card suit and at least a sound opener. I don’t think any of the popular modifications exactly solve this hand either.
Saturday, August 7, 2010
Update on the mysterious origins of the fatal hand
The fatal hand
Saturday, July 31, 2010
Not so fast (updated)
Here is a hand I enjoyed playing from our first-round loss in the Spingold. I was in 3C with
963 6542 QJ K873
KT54 7 K5 AQJ962
on the uncontested auction 1C-1D!(hearts)-1S-2C-3C. I considered the 3C bid very close; apparently at the other table they thought a long time and passed. Anyway, it’s nice to see the opponents can make 4D and probably 4H. Could I make 3C? They led a heart to the A and the DA. I dropped the DK in case I needed the entry; since I did this in tempo, I guess they were afraid I was 4-2-1-6 and they fatally played a second heart. I ruffed with the 9, played a diamond to dummy for a heart ruff, and played the CQ to the K, very pleased when lefty had stiff T. I could claim now; I eliminated the last heart with a high ruff, crossed to the C8 pulling the last trump, and led a spade planning to cover
The result was a 1-imp pickup when our teammates didn’t get in the auction either and were -90.
---------------------------------
The actual right way to play: I should use my trump entry before the diamond entry. This works just as well when the T drops, but leaves me better placed when it doesn't to make against both A onside and Qx or Jx onside, because I find out the trump position earlier. Work it out.
Friday, July 30, 2010
A 5-or-7 hand, at the one-level
I was kibitzing a hand from the Spingold QFs where Fantoni, in a 3-card ending, wound up having to guess whether the opposing trumps were initially 97/KJ54 or 95/KJ74. This was necessary in order to get out for 800 instead of 1100 in 1S doubled! In particular, declarer’s trumps were initially T863/AQ2. LHO had earlier overruffed declarer’s 8 with the 9, righty had ruffed a plain suit with the 4, dummy had ruffed with the A to avoid an overruff, and RHO had just ruffed ahead of declarer with the J, leaving a remaining trump position of
Q2
x Ky
T63
where {x,y}={5,7}. Now
The key is to ask yourself whether either defender had a choice of how to defend with either holding. For lefty, there is no inference whatsoever as he had no choice from either 97 or 95.
In real life, Fantoni ruffed with the T and was punished with -1100. At the other table, oddly, they got to 2H-X in a slightly stronger 4-3 fit and did two tricks better for -800. You can see the hand record here.
Thanks to vugraph operator Dan Wolkowitz for the joke in the title. He’s the best I’ve seen at operating accurately and making good comments at the same time.
Monday, July 12, 2010
The patient lived, but...
Sunday, July 4, 2010
Deep Six
After a slight bidding mishap in the round-robin, we wound up in a 6nt that (after a somewhat marked double-hook against an overcaller in his suit) required 5 tricks from AKJ62/T87 with plentiful transportation. Thanks to those juicy middle spots, you can pick up all 4-1 breaks with the Q onside after cashing the A in case of stiff Q, then running the T. In fact lefty did have Q9xx and we made it. I record this hand only because I can’t recall another instance of making a slam because of a crucial 6-spot.
Of course you can pick up Q9xx double-dummy without the 6, but only at the risk of blowing to 9x offside. This is hand 50 at http://usbf.org/docs/vugraphs/USBC2010/2ndRR46-54.PDF. Given the luck involved, I’m happy to report that both teams involved were going to qualify by at least 10 VPs regardless of the outcome on this hand.
Monday, June 28, 2010
Unusual sacrifice
After an unexpectedly long week, I must get back to work, so for the moment I’ll just finish the story of that highly successful “save” against 3nt from two posts ago. Note: We actually played more than any other team, since all the other semifinalists had QF byes.
Anyway this hand was from the penultimate match in the first round-robin. (Board 65 at http://usbf.org/docs/vugraphs/USBC2010/RR64-72.PDF.) At this point we were above water but certainly not a lock to qualify. Looking back at the hand records, I see I was 2nd seat not 3rd. I held AJ7 J3 KQJ98 J93 white/white and heard the auction I mentioned:
P-1D-2C-2H;
2NT-P-3NT-P;
P-??
Now here are the opponents in 3nt, and I know they have less than half the hcp. It has to be a bit tempting to double, but let’s give them some credit. They almost certainly have at least the two red aces and six club tricks for down 1…this was my first estimate. As I thought longer, I decided lefty almost had to have 7 clubs for both of them to have reasonable bids. Clubs were likely to be 7-3-2-1 around the table, and partner to have a light distributional 2H bid. So I wasn’t doubling…should I save? It’s certainly odd to save over 3nt with a balanced shape and no established fit, but partner must be distributional, so we shouldn’t be down very many with my having no wastage opposite his hope-for stiff club, and we might just make something. I decided to take a shot. I didn’t know if we should be in hearts or diamonds so I bid 4C, the famous pick-a-save cuebid. Partner chose hearts with K9x KQT98x xxx x and was able to wrap up 590 despite a 5-0 trump break when they could only tap him once – as Franco noted, both 3nt and 4H require clubs 7-2 to make. (Also, his S9 was good enough to freeze that suit from attack.) That was a 21-imp improvement on -400 since our teammates sold to 3D, -110. We seemed to gain momentum after this hand and blitzed this match to virtually clinch survival of the first cut.
Thursday, June 24, 2010
USBC seeding is fairly accurate
Tuesday, June 22, 2010
Cute problem from Round Robin
Saturday, June 19, 2010
USBC RR in progress
I’m resting between days of the USBC and won’t describe any hands in detail. Just let me tell you the auction on one of my favorite hands of all time. I was 3rd seat both white and it went:
P-P-1D-2C;
2H-2NT-P-3NT;
P-P-4C(!)-P:
4H-X-AP
Cold for +590…on a hand where the opponents had done very well to bid a cold 3nt on 19 hcp! They fell from grace and didn't save in 4nt, but the doubler did have 5 trumps(!). Try to reconstruct the hand :-). More after the event is over.
Saturday, May 15, 2010
K98xxx opposite J7x -- lose at most 2
Tuesday, May 11, 2010
On a lighter note
Tuesday, May 4, 2010
USBC RR Format: Avoiding Sitouts
I noticed that the current tentative schedule calls for RR1 to be 72 boards (81 appear on the schedule, but each team has a sitout for one of the nine 9-board matches.) Given that the conditions of contest call for “approximately 60 boards per day, erring on the low side,” 72 boards for a 1.5-day round-robin seems low. 10-board matches, 80 total, would be closer to ideal. One constraint which must be entering into this is that the sitout round takes time out of the day. With mostly 6-baggers, I doubt teams are clamoring for a sitout in the first stage. I want to suggest an 8-round movement without sitouts, which I have tried to design to function as smoothly as possible. (I did combinatorics research at one time and enjoy thinking about bridge movements. I hear there is a treatment for this.) The idea is that at any time you have 3 teams in a 3-way and the rest in 2-ways. Here is the movement:
Round 1: 1-2-3 4-8 5-7 6-9
Round 2: 1-2-3 4-9 5-8 6-7
Round 3: 4-5-6 1-8 2-7 3-9
Round 4: 4-5-6 1-9 2-8 3-7
Round 5: 7-8-9 1-5 2-4 3-6
Round 6: 7-8-9 1-6 2-5 3-4
Round 7: 1-4-7 2-6 3-8 5-9
Round 8: 1-4-7 2-9 3-5 6-8
Comments:
1. Three-ways create a slight security issue, because boards are played out of order. But with only one in each division at a time, the 3-ways can all be put in closed rooms, with the NSs expected not to leave their room for the 2 rounds and the EWs monitored as they switch rooms. Substitutions between halves of a 3-way are problematic and should probably be prohibited.
2. I recommend no comparisons be allowed between rounds 7 and 8. Comparisons can be allowed after other odd rounds if the 3-way teams are sequestered. The only teams with 2 3-ways have their second one at the end, and they could complain if everyone but them knows where they stand after 7. It’s probably best regardless of the movement, anyway, to disallow comparisons just before the final round.
3. This movement makes it impossible for all teams to play identical boards, to a slightly greater extent than do sitouts. I have tried to mitigate this issue, but a 3-way inevitably requires 3 sets of boards, so one of these must differ from the 2 sets played during the 3-way by the rest of the field. This mean 4 of the 36 matches will involve “odd boards,” which seems minor. The movement uses 12 sets of boards, with 8 being used in 4 matches each and 4 in 1 match each. Any pair of teams will play 6/8 or 7/8 sets of boards in common, while in the sit-out movement it would be always 7/8.
I believe that under this movement, 10-board rounds can be played in a reasonable time-frame. Only the first day might be long, with 6 10-board sets, but eliminating breaks after odd rounds would deal with this and doesn’t seem too onerous; many tables finish early anyway. Teams could be told “You can compare after odd rounds, but there is no extra time allotted for this.” The second morning would be very quick, 20 boards with no break, allowing plenty of time to transition into RR2. RR2, with an even number of teams, and the
Friday, April 30, 2010
Random seeding gripe
Tuesday, April 27, 2010
Foul trouble
In a professional basketball game, a player is disqualified (“fouls out”) if he is charged with 6 personal fouls. Observers of the NBA know that the direct effect of fouling out actually has less impact than the indirect effect of “foul trouble.” That is, if a player has a dangerous number of fouls, the coach will voluntarily bench him for part of the game, to lessen the chance of fouling out. Coaches seem to roughly use the rule of thumb that a player with n fouls should sit until n/6 of the game has passed. Allowing a player to play with 3 fouls in the first half is a particular taboo. On rare occasions when this taboo is broken, the announcers will invariably say something like, “They’re taking a big risk here; you really don’t want him to get his 4th.”
Is the rule of thumb reasonable? No! First let’s consider a simple baseline model: Suppose I simply want to maximize the number of minutes my star player is in the game. When should I risk putting him back in the game after his nth foul? The phrasing is deceptive, because I shouldn’t bench him at all! Those of you who haven’t been brainwashed by the conventional wisdom on “foul trouble” probably find this obvious. The proof is simple: if he sits, the only thing that has changed when he gets back in is that there is less time left in the game, so his expected minutes have clearly gone down (in fact the new distribution on minutes is first-order stochastically dominated, being just a truncation.)
OK, while I believe the above argument is very relevant, it oversimplified the objective function, which in practice is not simply to maximize minutes. I’ll discuss caveats now, but please note, there is tremendous value in understanding the baseline case. It teaches that we should pay attention to foul trouble only insofar as our objective is not to maximize minutes. I am very comfortable asserting that coaches don’t understand this!
First caveat: players are more effective when rested. In fact, top stars normally play about 40 of 48 minutes. If it becomes likely that a player will be limited to 30-35 minutes by fouling out, we may be better off loading those minutes further towards the end of the game to maximize his efficiency. Notice, though, that this doesn’t lead to anything resembling the n/6 rule of thumb. It says we should put him back in, at the very latest, when he is fully rested, and this isn’t close to what is done in practice. In fact players often sit so long the rest may have a negative impact, putting them “out of the flow of the game.”
Second caveat: maybe not all minutes are created equal. It may be particularly important to have star players available at the end of the game. On a practical level, the final minute certainly has more possessions than a typical minute, but it also has more fouls, so maybe those effects cancel out. I think the primary issue is more psychological: there is a strong perception that you need to lean more on your superstars at the end of the game. I think this issue is drastically overrated, partly because it’s easy to remember losing in the last minute when a key player has fouled out, but a more silent poison when you lose because you were down going into that minute having rested him too long. By the way, my subjective sense is that the last possession is more similar to any other than conventional wisdom suggests: a wide-open John Paxson or Steve Kerr is a better bet than a double-teamed Michael Jordan any time in the game. On a couple of major occasions,
One more psychological caveat: a player who just picked up a foul he thinks is unfair may be distracted and not have his head in the game immediately afterward. This may warrant a brief rest.
Final note: Conventional wisdom seems to regard foul management as a risk vs. safety decision. You will constantly hear something like, “a big decision here, whether to risk putting
There are well-documented cases in the last decade of sports moving towards a more quantitative approach, so maybe there is hope for basketball strategy to change. The foul-trouble orthodoxy is deeply ingrained, and it would be a satisfying blow for rationality to see it overturned.
*Final outcomes are binary, so the classical sense of risk aversion, involving a concave utility function in money, doesn’t apply at all. But there is also a sense of what I call “tactical risk”: a decision may affect the variance of some variable on which your probability of final success depends in a convex (or concave) way. I might write an essay sometime on the different meanings of “risk.” Anyway, here you would presumably should be risk-averse in your star’s minutes if ahead, risk-loving if behind. But this is rendered utterly moot by first-order stochastic dominance!
Monday, April 26, 2010
The dog that didn't ask
A friend of mine got “accidentally jobbed” by “accidental UI” in a very simple auction last week. How do you think a director or committee would treat this?
1S-P-3C(nat, inv, alerted)-X-All pass
Now, clearly X here is takeout, right? Well…except the doubler never asked what 3C was. He had a 5-card club stack and assumed 3C, alerted, was
It’s clearly wrong for this to stand, because, however far this was from the players’ intentions, it gives them the ability to make takeout or penalty doubles in the same auction. If you agree, would you trust a director or committee to get this right? (I wouldn’t.)
BTW, it is impossible to avoid conveying UI on this hand, unless you follow the “always ask regardless of your hand” principle, which very few do. If the club stack asks, is told 3C is natural, and passes, the message is clear unless he is an always-asker. That particular UI would have been fairly innocuous on this deal, but the problem remains.
I guess if I were arguing this hand with a committee, one of the strongest points is that doubler ignored the skip bid.
Thursday, April 8, 2010
Entryless Squeeze with Nothing Resembling the Count
You know that an ordinary simple squeeze requires that you have all the tricks but one. You probably also know that if you have three threats against one player, or a suit-establishment threat, the squeeze can function with all but two tricks. But did you know that if both conditions hold, n-3 can be enough? Or that you don’t need any entries?
In a rubber bridge game, this 6-card ending happened, with spades as trumps:
North: xx xx Jx ----
West: T ---- xxxx x East: ---- QJ KQ Jx
South: Q x x KT8
As you can see, South has 3 of the last 6. When he plays a trump to his Q, a red-suit pitch by East lets him establish and score a 4th trick, and a club pitch gives two tricks. All this with no entry in any threat suit! Yes, the last trump is a sort of entry-surrogate, but this doesn’t at all resemble a typical ruffing squeeze.
Since this took place at a bar, I hope declarer, Dan Wilderman, doesn’t mind my saying he may have stumbled on this position a bit by accident. Nevertheless, this should definitely be the Wilderman (or, the Wild Man?) squeeze.
Monday, March 22, 2010
Six-card ending; conclusion
See two posts ago for the problem.
The club pitch strongly implies that lefty was 2-4-2-5, so the ending looks something like:
N: --- AJ7 --- Q9x
W: --- ??? --- JTx E: Tx ?? 75 ----
S: ---- Tx 82 Kx
If West has both heart honors, you can make it by straightforward play. If East has the K, you can’t make it – the position is frustratingly close to a double squeeze, but there just isn’t a way to rectify the count without East cashing the setting trick. What if West has the K and East the Q? That is how it was at the table. If you cash the D8 now, at trick 8, West has three losing options. A club pitch is obviously no good. A low heart pitch lets you set up hearts while keeping East off lead, by a standard avoidance play. So should he pitch the HK? Then you cash the Q and K of clubs to execute a standard strip-squeeze against East (who must pitch his spade winners and get endplayed or bare the HQ.)
The catch? Suppose West pitches the HK, then when you cash your clubs East pitches a spade and a heart. So East just bared the HQ, right? Maybe. But maybe West has made a genius *fake* unblock holding both heart honors, and East has alertly cooperated (if he threw his spade winners from his entryless hand you would give him a diamond and claim.) I say if they do this to you, gracefully go one down, write the hand down carefully and you get to be the journalist for the Defense of the Year.
By the way, it is tempting to cash the CK first in the 6-card ending, to check the break. But then West can pitch the HK from K-empty and beat you, because you no longer have an endplay threat against East.
Friday, March 19, 2010
A small extra chance
North: 843 J3 AKQT84 K4
South: AKQT2 AT954 52 A
We arrived in 7S by South and I got a club lead. With no side entry to dummy, you basically need both spades and diamonds to come in – thanks to your tens this is about a 62% chance. Do you see a small extra chance, about 2-3%?
I didn’t see the small extra chance initially, but when I cashed two top spades I was alert enough to notice that the J9 fell on my right, and appreciate that the 8 had appreciated. I went to a diamond, pitched my diamond on the CK, ruffed a diamond high, and could go to the S8 claiming even if diamonds were 4-1. They were 3-2, but I still like the story. The opponents stopped in 6, for one of our few pickups from the GNT final.
Wednesday, March 17, 2010
A nice 6-card ending
Reno was a disappointment for me, but congrats to Franco and Andy as the inaugural Platinum pairs champs. (Most of you have seen Franco's blog, linked from this page.)
A nice catalog of pretty double-dummy 5-card endings with some practical value is George Coffin’s “Great 88,” reproduced at Richard Pavlicek’s web site here.
North: AKx AJ7xx 3 Q9xx
South: xxx Tx KJT82 AKx
N-S arrived at 3nt via an uncontested auction where South opened 1D and rebid 1NT, then North relayed to reveal his exact shape and South chose 3nt.
The play began SQ ducked; spade to dummy; diamond to J and Q; D9 to T; DK to East’s A (West pitched club);spade to dummy (West pitched heart); club to A (both following). This left:
N: --- AJ7 --- Q9x
S: ---- Tx 82 Kx
with declarer having taken 4 tricks, and looking at 4 more. How should declarer continue?
Sunday, March 7, 2010
No crying in bridge
GNT in progress
Friday, March 5, 2010
District GNT this weekend
Wednesday, February 24, 2010
Textbook Problem
Yesterday I was fortunate to get dealt a cute textbook defensive problem. To see the hand record, click here.
My play now doesn’t seem perfectly precise to me; if declarer had AKJxxxx Jx Q Jxx I would need to cash the CA and then play a low diamond so there is no endplay later. Always room for improvement! The DK felt sexy and worked on this layout, but with the J in dummy a low diamond is better. I also must point out my play would be a disaster if declarer had AKJxxxx J Qx Jxx. (We can infer from partner's non-heart lead he doesn't have QJxx(x) there, making the danger layouts less likely.) Perhaps I should cash the CA and hope partner gives a suit-preference signal. In any case, I enjoyed this hand. Usually declarer knows the most about the key issues of the hand; it's nice when you know the most as a defender and can take advantage.
Monday, February 15, 2010
Follow-up to post-preempt decision
Well, at the virtual table I passed here without much thought. As Alex mentions in the comments, I am in general a devoted non-sacrificer. But let’s revisit this. What is partner doing? Based on his failure to bid anything the first time, or to bid 4S the second or third time, we can be confident he does not have a diamond-suit-plus-spade-fit kind of hand. No, he has a bucketload of diamonds. In context, I think we have a nice fit; when I preempt, he must expect about 1 card in his very long suit on average. Two and a ruffing value (if they don’t pull my trumps) is a nice bonus. It was a bold action to save over 3nt, and he must have a very long semi-solid suit. Can we raise the sacrifice a level? In retrospect, I think we can. Of course, I have come under the influence of seeing the hand record, here.
Thursday, February 11, 2010
Funny post-preempt decision
In a friendly imp match on bridgebase, I had an interesting decision: White/red, I had AKT9xxx Txx xx x. I was second seat, and it went:
1C-3S-X-P:
3NT-P-P-4D;
P-P-4H-P;
P-?
Any thoughts?
Sunday, February 7, 2010
Just another 2-imp swing
Dummy: Axx QJ8xxx AJx x
Declarer: x Ax KQ9xxx Kxxx
Declarer opened 1D in second seat, white/red; the full auction was P-1D-1S-2H; P-3D-4C-5D; AP. Dummy had a tough call over 4C -- as it happens, even with partner having Ax in hearts, diamonds might be the best game. Discussion of the play below…
Vulnerable, LHO must have almost everything to bid at the 4-level; if he is 6-5, I suppose he could be missing the HK. Running the HQ next seems to cover almost every case. If it holds, you play a club to the K (to keep righty off lead in case hearts 4-1) then have enough tricks, with at least two club ruffs in dummy followed by pulling trumps; maybe 3 club ruffs if lefty has no trump to lead. If, more likely, the heart loses, your plan is to use the long hearts, which works unless the HK was stiff (lefty can’t have 4). You even survive diamonds 4-0 when hearts break. After unblocking HA, you play DK, DJ and start hearts; righty is helpless since you can overruff and pull his trump, and still have just enough pitches. I can also see an argument for starting hearts with the ace, in case lefty has stiff K. This may lead to more complicated play when righty has KTxx and they tap dummy, but I think you always survive.
At the table, LHO held KQTxx Kxx –- AQJTx. I don’t know declarer’s actual play, unfortunately, but he went down 1. Maybe he cashed a high trump from dummy before working on hearts, which looks natural but is fatal on the 4-0 trump break. The lesson is not to pull a round of trumps “just to check” unless you are really sure it doesn’t cost a vital entry; this is easy to miss here because you only need that entry on 4-0 trumps.
Monday, February 1, 2010
Not quite
(Some spots corrected from original post--thanks, Kenny.) I played in a Chicago-area sectional Swiss yesterday with Drew Becker and Kenny Zuckerberg/Bill Drewett. It was a good turnout numerically, with about 50 teams. As for quality: There were two teams in the (stratified) field with national-caliber players, but as for the rest …it felt as if every time we came back with a moderate card, our teammates had a 1400 and an 800 for a blitz, and vice-versa! I know there were some decent teams out there, but we didn’t seem to be playing them. After 6/7 matches we were undefeated, had beaten both good teams (in close matches) and had 101 VPS. In the Swiss I wrote about in July, 100 clinched for my team after 6, but that was a flighted regional; yesterday 101 was good for only a 1 VP lead over Katz/Demirev, Miller/Carmichael, and Lehman/Melson. They would be playing the other star team, so our chances were fairly good. Alas, we suffered our first loss by 1, they won by 2, and that made the final score 111-110. I was left to contemplate the overtricks I had blown against 2NT on the final board of the day. But if there was any justice, the imp my partner earned on defense against the eventual winners back in our second match would have proved decisive:
North: JT9x Qx QJTxx Ax
West: KQxx Kxx Axx KQx East: xxx xxx K9xx JTx
South: Ax AJT9x 8 xxxxx
Partner (West) opened 1NT, passed around to South, who balanced with 2C showing hearts and a minor; North bid 2D (denying 3 hearts) and South corrected to 2H and played there. Drew led a small trump; declarer won the Q and played ace and a club…and I won the trick, because Drew had dropped an honor under the CA. I managed to get a second trump on the table, and this defense held declarer to his contract. This was a 1-imp gain for our side (see comments for the sequence at the other table.). Sadly, this particular imp was not worth the VP we would need at the end of the day.
Of course, a diamond underlead could accomplish the same thing…maybe my club plays should convey suit-preference if partner doesn’t unblock, so he can underlead, but that is hardly routine. Finally, notice that if declarer decides that not letting me win a club trick is the vital issue, he needs to lead a club from hand so he can duck if partner splits. This might be the wrong play, of course; it could look bad on poor breaks.