22 two lines of play with little

22 two lines of play with little to choose between them

ª A 10

¨ K J 3

§ A Q 10 6 5 4 2

ª J 4 ª K 6 5

¨ 10 9 7 ¨ 8 5 4

§ K J 8 § 9 3

ª Q 9 8 7 3 2

¨ A Q 6 2

§ 7

Our opponents reached 6ª and the only problem is how to play the trump suit. There are two alternatives – finesse ª10 or play ªA and lead ª10 for a finesse. So which is best?

The possible layouts of the spade suit are shown in the following table. 5-0 breaks (3.91%) are ignored as there is no way to succeed. Also those layouts where West has to play an honour are trivial. Also, if West has ªK J x x there is no way to succeed. The probabilities shown below ignore these combined possibilities which total 21.44%. The remaining probabilities are normalised to 100%.

If East holds four spades a trump coup can be arranged in some cases which is fairly likely.

	West	East	Prob %	Finesse ª10	Play ªA and finesse ª10
1	ªx	ªK J x x	10.79	Loses	Wins if a trump coup can be established
2	ªx x	ªK J x	12.95	Loses	Wins
3	ªx x x	ªK J	4.32	Wins	Wins
4	ªJ x	ªK x x	12.95	Wins	Loses unless East rushes in with ªK
5	ªJ x x	ªK x	12.95	Wins	Wins
6	ªJ x x x	ªK	3.60	Loses	Wins
7	ªK x	ªJ x x	12.95	Wins	Wins
8	ªK x x	ªJ x	12.95	Loses	Wins
9	ªK x x x	ªJ	3.60	Loses	Wins
10	ªK J x	ªx x	12.95	Wins	Loses

So finessing ª10 immediately wins 56.12% and playing ªA first and then finessing ª10 wins 50.32% outright but there are the extra chances that a trump coup could be performed which I would estimate at least half the time so that is an additional 5.39%. that makes the odds virtually equal. Given the extra chance that East might play ªK it swings it marginally in favour of playing ªA first. I must confess that I would choose that line since the trump coup is something to be proud of while finessing isn’t. It was not our night and declarer finessed ª10.

One final thought. If West held ªJ x x x and led the suit declarer would definitely choose the wrong option! Maybe I can convince someone to lead from that against my slams.