[inquiry]

After reading Luis's thread on "Tips for counting declarer's hand" http://forums.bridgebase.com/in...ay;threadid=586 I decided to explorer one of his topics more: drawing inferences from the opponents bidding. For this thread, however, I am not "limiting" it to counting Declarer's hand, as you we should discuss counting defender's hand and yes partner's hand (and by inference, declarer's hand).

The title for this thread is take from Hugh Kelsey's excellent book "Bridge Logic," it my copy is very, very old and it may have been reprinted with a new title...but an excellent book.

In his thread, luis said "Don't rely in bids from obfuscated or inexperienced players, sometimes they just bid the wrong thing.If you are playing against good players then pay a lot of attention to the bidding, there's a lot of information to get from the auction to help you count the hand. "

This is, of course, a generalization, and generalizations have a tendency to be wrong on both ends (including this one :-) ). You draw inferences at your own risk against any level of opposition. But if you ever read an expert bidding poll, you will see that even "experts" can't agree on what a right bid is with a given hand. Let me give just one example from right here in the BBF...

In a thread on 1c or 1d... this hand came up.

S: KXXX
H: A
D: KTXX
C: AQXX

Some people think opening 1C is right, most 1D, and one player prefered opening 1NT because ""This looks like 15-17 HCP, balanced to me". " So that is three different opening bids. But even then, on rebids, the auction took a further turn after a 1H response, some after opening 1C advocate a "light" reverse to 2D (the reason for opening 1C). some opened 1D and rebid 2C, and a few like John Good and myself, open 1D and rebid 1S over 1H. (see the link if you are interested in the discussion http://forums.bridgebase.com/in...tart=0#lastPost )

It is this disagreement in the bidding that lead Luis to warn about drawing inferences from "inexperienced" bidders. But, I think Luis would agree that the 1NT opener and John are both experienced, but their treatment for this hand is quite different. In fact, I expect most inexperienced bidders would open 1D (suit below singleton) and rebid 1S (biddable suits up the line)... just like me on this hand.

Let's see if we can draw a list of realatively safe generalizations about opponent's bidding and go from there....

[1] An opponent who over calls at the 2 level has 5+ suit
[2] A opponent who bids, and rebids an unsupported suit in competition generally has 6+ suit
[3] A one notrump opening bid or NT rebid generally does not include a singleton
[4] An opponent playing 5 card major, will open a major with 5+ suit.
[5] Opening preemts at the three or higher level have long suit (6+ 3 level, 7+ 4 level)...playing against some opponents, these preempts will be 5+ 3 level, and 6+ 4 level if they are not vul and you are).
[6] An opponent who bids like he has stregnth and legnth is suit, generally has stregth and length (yes, I know what a psyche is).
[7] An opponent with a seven card suit, not vul, will bid it.. hcp or not.
[8] An opponent with a smattering of hcp and 6-6 or 6-5 hand will find some way to show his suit.
[9] An opponent with 13 hcp will not pass if given an opportunity to open (and some players will not pass with 11 hcp -- for this and the preempt thing, it pays to know your opponent's style).
[10] Opponents with 4 card support raise their partners rather than bidding something else
[11] Opponents playing support doubles will have two or less in their partner's suit if they neither double (to show 3) or raise (to show 4).

Feel free to add to this list, and show any good example hands were such inferences might be useful to declarer or defenders.

Ben

[inquiry]

This echo...is a shout... playing IMPs in BBO, here is the hand, all vul...


S-K76
H-AT7
D-QJ86
C-K63

S-AJ742
H-QJ
D-K43
C-A84

Bidding

W N E S
P 1D P 1S
P 1N P 2C *2C = nmf checkback
P 2S P 4S
X P P P

The DOUBLE is more than an ECHO, it is a shout. Opening lead H5... to the King and then Diamond FIVE back, you play low and West wins the ACE, and continues the DIAMOND-TEN to DIAMOND-2 and your KING.

If you haven't done so already, time to think a bit. You have lost 2 tricks already. And the opponents have very good SPADE spots... the QT98x. You can't afford to lose two spade tricks. What do you think West was doubling on? He has at most a club honor (surely with QJ he might have picked a club rather than a heart from dirt), and the diamond ACE. Isn't it clear he has the spades? If he has five spades you are down. But with the clue from the bidding and play can you make if he has four spade?

The answer is yes. Without the double, you would surely go down, as there would be no reason to try the risky play. You start by leading a spade to the ACE, both follow. You can only afford 1 Spade loser, so you have to prepare an endplay on WEST, so you cash your high heart for a club discard. Next you cash two clubs.... to reach....

S:76
H: -
D:QJ
C:x

S:AJ54
H:-
D:x
C:-

You will need to be able to cash one diamond and then ruff a club or a diamond.... for the endplay. So you lead the diamond Queen. When RHO shows out, you know which minor to lead next from dummy.... (another diamonds, as diamonds are 4-2 with West having four. So you lead the second diamond and ruff, as LHO helplessly follows suit. Now you lead a low spade in this ending....

S-xx (plus a Club)
S-QT9 junk
S-AJx

West wins the Spade 9, but then has to lead from the QT into your AJ. Again, you would have NEVER made this without listening to the bidding. The double actually HELPS you.

Ben

PS.... I misplayed this one in real life, I tried to ruff the club and then lead the diamond, so I ran afowl of West having doubleton club, he overruffed and I still had to lose another trump. I listened to the bidding, arrived at the correct conclusion, but then failed to apply sound bridge logic to playing the minor cards in the right sequence :-[ ARRRGGGHHHH. lol