[EarlPurple]

Line A seems to require one of 3 finesses and is thus approximately 87.5%.

Line B appears to make whenever:

♠A onside (50%)
clubs are 3-3 (36% of remaining 50% making 18% - 68% so far)

♥K drops singleton (12.5% of the remaining 32%, which makes 4% total - 72% so far)

clubs are 4-2 but with shortage singleton heart or HK doubleton.
(Difficult to calculate this one)

clubs 4-2 with CJ falling, and you can overruff East and lead a diamond, with West holding both ♦K and ♠A and either no more trumps or just the king (so he can't reach partner). Thus something like:

♠Axx ♥Kx ♦Kxxx ♣9xxx [] ♠ QJxxx ♥xx ♦xxxx ♣Jx

So you won the ♦A, unblocked clubs and led ♥J to ♥A (West not covering), then led ♣Q, East ruffs, you overruff and lead a diamond. West might cash his ♥K but then must lead a diamond to put you back in dummy or a spade away from his ace.

[1eyedjack]

EarlPurple, on Jun 28 2004, 03:18 AM, said:

Line A seems to require one of 3 finesses and is thus approximately 87.5%.

I am not sure that the conclusion follows from the premise.

If the person on lead lacks the ♠A then he might be more inclined to lead ♠ than if he holds it. His failure to lead ♠ increases the likelihood of ♠A sitting over the ♠K.

If the person on lead lacks the ♦K then he might be more inclined to lead ♦ than if he holds it. His decision to lead ♦ increases the likelihood of the ♦K sitting over the ♦A.

Don't ask me to quantify this effect, but I doubt that the effect is trivial.

[EarlPurple]

West may well lead away from ♦K. If North has shown a decent club suit then bid to game, the defence may not have time to wait quietly for a diamond trick, and lead them can be essential. And in that situation, some players may also have led ♠A.