Thursday, April 2, 2009

Upgrades

Have you noticed that your partners and opponents (not you, of course – you are a very sound bidder) seem to be more likely to have 14 hcp than 17 for a 15-17 notrump? This might not be an illusion, and they might not be wild bidders, either.

Let’s assume that 5-3-3-2, 4-4-3-2 and 4-3-3-3, including 5-card majors, are considered balanced. The 5-3-3-2s represent about 1/3 of the balanced hands. I feel safe in saying a typical expert upgrades the majority of these. Of course, you wouldn’t upgrade QJ Jxx Jxxxx AKQ :-) – but you would upgrade AJT9 KTx Kx KT9x or the like. Let’s assume 1/3 of all balanced hands are upgraded, for now. I don’t think this represents wild overbidding. Subjectively, I’m fairly certain there are people who upgrade more than 1/3 of hands, maybe close to ½.

The important objective statistic is that balanced 14s are about 2.3 times more common than balanced 17s. (Thanks to Richard Pavlicek’s excellent webpage for some of these stats; as he notes, the hcp distribution is different for balanced vs. unbalanced hands.) If your opponent (or partner) upgrades 1/3 of the 14s to 1NT, and 1/3 of the 17s to the 18-19 range, then when he opens a 15-17 1NT you should assume he is about 1.15 times more likely to have 14 than 17! If all the 15s and 16s are treated as 15-17, the overall percentages are that a 15-17 NT will contain

14 hcp: 17% 15: 39% 16:30% 17: 14%

Just hypothetically, if someone upgrades half of all balanced hands, the percentages become:

14 hcp: 24% 15: 37% 16:28% 17: 10%

So 14 would be almost as likely as 16, and much more likely than 17.

7 comments:

Memphis MOJO said...

I don't upgrade as much as I did in a younger day. My partners are aggressive and I want them to push after I open 1NT.

This hand is in the May Bridge Bulletin It's Your Call:
K5, AKJ10, QJ107, 875.
Several of the experts complained that they would have opened 1NT (I would have, too, clearly) because the 10s support other honors.

Anonymous said...

Hi Jon,

There is another aspect that skews 14:17 ratio even further. Many people upgrade 17s to 1.5NT.

Regards,
Alex

Alan Applebaum said...

This is a subject near and dear to my heart. I think it is more a matter of partnership rapport than anything else. With a conservative partner I upgrade probably 1/3 of the 14s and 1/3 of the 17s. With a "normally aggressive" partner that will invite with most 8s over 1NT and most 11s over a 1NT rebid, maybe 1/10 of each.

Does anyone ever downgrade? I do if I have AK, KQ or QJ tight but that's about the only time.

Jonathan Weinstein said...

Hi Alex,

I actually took into account the upgrading of 17s. That does have a significant effect.

JLW

Kenny Z said...

Not that I don't like the occasional meaningless diversion from work, but is there any practical value in knowing these statistics? Should they help you in some way during the auction? If partner is "upgrading," shouldn't we just trust his judgement and continue to evaluate our hands as if we are responding to a 15-17 point 1nt opener?

Jonathan Weinstein said...

As far as partner goes, I'm pretty much with you, Kenny -- the whole idea is his hand should "act like 15." If you're defending and trying to count the opponent's hcp, it might be nice to know that someone who upgrades like a "normal expert" will have 14 as often or more often than 17.

The Pretender said...

I now play a 15+ to 18- 1NT in 1/2 seat, so I know what it's like to constantly evaluate upgrading/downgrading.

I always try to think of bridge as the correct mesh of two hands. I find that most players just tend to decide whether a 14 is "good" and upgrade. When I play a 15-17 NT, my general upgrading rule is this: If I want to be in 3NT opposite a good 9 or a normal 10, then I open 1NT. I also believe in upgrading 5 card suits more aggressively the stronger my hand is. ie. I'm more likely to upgrade a 19HCP to 2NT than a 14HCP to 1NT than a 11HCP to an opener. What's the point of upgrading a good suit if you can't stop the opponents enough to set it up?