[nullspace]

In this hand
Dummy (north)
C K 3 2
D K J 10 9
H 3 2
S 5 4 3 2

Declarer
C A Q J 10 9
D A Q 2
H
S A J 10 9 8

Contract is 6S (lead is hearts)
According to the software line of play after ruffing the first hearts, cross to dummy diamonds, finesse spades. If fail, ruff the hearts return and cross to dummy clubs, finesse again.

What i do not understand is that since the contract have a 9 card fit, why not cash Ace first (catches K/Q singleton 24.8%) and if fail lead J (40.7% there is a 2-2 break). In the software line of play, they are guessing East have 3 Spades (24.8%) and risk a void in either dimes or clubs (5.4%). Which play will you guys find superior to the other?

[manudude03]

The double finesse is 76% as opposed to the 65.5% total chance you've quoted for your line.

"8 ever, 9 never" only applies when you're only missing the queen.

[Mbodell]

 nullspace, on 2013-February-02, 08:46, said:

What i do not understand is that since the contract have a 9 card fit, why not cash Ace first (catches K/Q singleton 24.8%) and if fail lead J (40.7% there is a 2-2 break). In the software line of play, they are guessing East have 3 Spades (24.8%) and risk a void in either dimes or clubs (5.4%). Which play will you guys find superior to the other?

The A first doesn't win when it catches K or Q singleton. It wins the first round but loses to the person with Qxx or Kxx for one loser. Finesse twice has the same result of 1 loser (you lose to the stiff, but win the Qxx or Kxx hand). So those situations are a tie between the two lines.

Playing the A first wins when the person behind declarer has KQ doubleton offside. That is the only trump layout the A first is better. Finessing twice is better for KQx onside and there are two of those (KQ7 and KQ6). While one 2-2 break (KQ offside) is slightly more likely than one 3-1 break (KQ7 say), two 3-1 breaks (KQ7 and KQ6) are more likely than one 2-2. Finessing twice also covers KQ76 onside (that is a 4-0 break), although I haven't verified you have enough tricks to handle that on this hand.

[Free]

Cashing the Ace basically plays for any 2-2 holding, K-Qxx or K-Qxx. Finessing twice handles the same hands except KQ-xx. However, finessing twice also handles x-KQx and void-KQxx. You basically give up 1 holding and get 3 (x-KQx has 2 possibilities) in return.

[gnasher]

Hoping to make against a 0=4 break is rather optimistic. The play would go: ruff the lead, diamond to dummy, spade to the nine (West showing out), club to dummy, spade to the queen and ace, three more clubs throwing dummy's last heart, spade to East's king, heart ruffed in dummy, diamond to hand, draw the last trump. Hence we'd need their shapes to be 0841=4324 or 0931=4234.

(Writing that with the suits upside down was *incredibly* difficult.)

[barmar]

The normal order to list suits is spades, hearts, diamonds, clubs. Even better, use the hand diagram tool to enter them -- click on the "spade" symbol in the toolbar above the input editor.