Thursday, November 21, 2013

Using predealt hands in small games

Here in the boondocks, our club games usually range from 7 to 9 pairs.  But I would like for us to take part in the Common Game.  We obviously can not afford to buy a $4000 machine to predeal the hands, or even to shell out $1600 for four "hand-duplicators".

The only option is to print out slips for each of the hands and then have each pair make the hands they are not going to play.

If we have 3.5 tables, this is easy.  We can run a 28-board, 7-round Howell and, assuming that pair 7 is the sitout ("phantom") pair, each pair deals out the boards they would have played against pair 7.

For reference, for a 3.5 table game, these are the boards that each pair needs to deal out before the game starts (7 is the sitout):
PairBoards
113-16
21-4
317-20
45-8
521-24
69-12
825-28

Similarly, for a 4.5 table game, we can run a 27-board, 9-round Howell and every pair can simply deal out the boards they would have played against pair 7.

Again, for reference, for a 4.5 table game, these are the boards that each pair needs to deal out before the game starts:
PairBoards
119-21
213-15
31-3
410-12
516-18
64-6
87-9
922-24
1025-27


But what can we do if we have 4 full tables? Currently, we play a 28-board, 7-round Howell with no sitouts. Everyone plays every board and every pair plays every other pair. These are the best games at the club now.  I can not figure out how best to use predealt hands with this configuration.

One option is to decide that the most important aspects are (a) to play every other pair and (b) play at least 24 boards. We can run the game as 5 tables, 8 rounds and 32 boards, with each pair making up the boards they would have played against pair 9/10 (those pairs are relaying on this movement, so it is only one set of 4 boards that everyone needs to make).  The drawback is that we will have two sitouts, where without predealt hands, we had none and the games will take way too long.

UPDATE:

I asked about this on Bridge Winners and someone suggested that I look at a paper on this topic by Matthew Johnson.  His code no longer works (and tries to do everything including double dummy analysis), but the underlying idea is simple and elegant -- take a sorted hand, deal it once according to a random permutation and then deal it again, this time to the target combination of cards.

So, I went ahead and implemented the algorithm. It is less than 200 lines of Python code ... The program is here and this is what the output looks like.  The output can be printed out, cut into pieces and used to deal the hands.

So, in summary, to use predealt hands in small games:
  1. If you are running a Howell movement with 3.5 or 4.5 tables, have everyone make the hands they would have played against the sitout pair.
  2. If you are running a Mitchell movement where everyone does not play all the boards, have the pairs make the boards they will not be playing.
  3. If you are running a full game, use the 2-stage process above. The predeal.py program will provide the instructions.  There is very little information leakage and people can play the boards that they make.

Poker on the last round

At the weekly club game, our last round was against the pair who usually win. "How are you guys doing?," one of them asks as he sits down. "Pretty good," I reply.

Maybe if we have a good round against these guys, we can win tonight.

First board: they open a 11-13 NT, raised to 2NT and they play there. At other tables, the auction goes 1D-1NT.  1NT played from the other direction turns out to be easier to defend.  First board to the bad guys.

Second board, the bidding is wild.  It goes:
W
West
N
Pard
E
East
S
Me
1
1
4
4
5
5
6
Dbl
All Pass

6H doubled, going 2 down is par on the board -- they are cold for 5S and we are cold for 4H. This turns out to be an average board -- some pairs are in spades and others are in hearts.

Third board is another wild board, but this time they forget to double us and we get a top after going down 3 in 5H.   6C made, as did 5NT their way.  One to the good guys.
W
West
N
Pard
E
East
S
Me
4
5
5
All Pass

So, last board of the night, for all the marbles.  Another wild hand (I am South):


West made the best possible lead, of the King of diamonds.  Click Next to follow the play.

West, who had the 4th spade and the queen of diamonds, gets squeezed as I run off the hearts. When East didn't return a diamond, I could see this squeeze coming, and so as a flourish, I even discarded the ace of clubs!

I was very happy to have made six on a squeeze, but it was a bottom board for us. Turns out that everyone was making six (probably misdefense by West), but all the other pairs were in 3NT.  How? Perhaps the bidding went 1D-1H-2NT-3NT?

After all the wildness, the round itself turned out to not matter. We ended up winning by a couple of boards.

Sunday, November 17, 2013

This won't happen again

I religiously play the bridgez tournament everyday (if you don't have a Windows machine and therefore can not play using the wbridge5 client, then use this website to play the bridgez tournament).

Inevitably, the wbridge5 robot places very high in the rankings, perhaps because it understands the opponents' and partner's signals perfectly.   In the Nov. 17 tournament, however, I managed to beat the wbridge5 robot. In fact, it looks like I beat out all but one of the humans.


What this probably means is that I took a few against-the-odds positions and they paid off. Still, I'm happy to have beaten the robot.  That probably won't happen again.

p.s. Lest you get the wrong idea:  67% is way outside my usual range -- I currently average around 55%.

In my dreams

How bad is it to squeeze your opponent, and then let them slip away because you call for the wrong card?

Happened to me on this hand at a recent Sectional.  I was South, playing 3NT and this is how the play should have gone (click Next to see the plays):


I had the count of the hand and had watched the discards, so I knew West was down to three hearts, a club and two spades. But I got so excited that I was going to carry out my first squeeze that instead of calling for the top spade from dummy, I called for the top club.

How sad is that?

Thursday, November 7, 2013

Sad one no trumps

Playing 2/1 with a 15-17 NT doesn't mean that opening 1-NT when you have a balanced hand and high card points in that range is automatic.  There is some room for judgment. In the club game yesterday, there were two such hands, and I managed to get it wrong both times.  See if you can do better.

Do you open 1NT in first seat with this hand?
S
Me
KJ9xx
AKx
Kxx
Qx


Reasons to open 1NT: You have a balanced hand, and points in the short suits. The spade suit is good, but not great.  You have no good rebid if you start out 1S.
Reasons to open 1S: It gets your suit across. The field will open this 1S and at matchpoints, it's good to stick with the field. You have no way to discover a 5-3 fit after you start out 1NT.

I opened 1NT.  On this hand, partner turned out to have 10 points, 4 hearts and 3 spades. 4S made 5 at every table after the auction went 1S-3S. 3NT went down 1 after our auction went 1NT-2C-2S-3NT.

How about this hand?  Would you open it 1 NT in 3rd seat?
S
Me
KQ
Qx
KQJ10
Q10xxx

I do have 15 high card points, but no aces and the texture of the hand is awful. I decided to downgrade it and open it 1D (can't open 1C and reverse either, can I?) showing where I lived.  Partner bid 1H and when I rebid 1NT, he rebid 2H.  2H played from his side went down 1.  If you had opened 1NT, partner would have transferred you to hearts and passed. Played from your side, the club queen is protected and the strong hand is not visible. Defense is considerably harder, and you'll make either 8 tricks or 9.

After the game, I didn't even wait to learn how we did -- I'm sure something awful, well south of 50%.

p.s. Bridge Winners polls on these two hands:  http://bridgewinners.com/article/view/bidding-problem-2999/ and http://bridgewinners.com/article/view/bidding-problem-3000/.  I have gotten into the habit of posting hands that posed me problems. The comments and votes help me learn how to think about these types of hands better.