[smerriman]

If I enter this card combination into Suitplay:

KQT76
53

it first tells me there are more than 26 possible strategies(?!), and only some will be shown.

If I then take one of the strategies for 4 tricks, and step through - say, 3-4-Q-A, 5-2 and it tells me to insert the 6 or 7, guaranteeing failure.

Anyone seen something like this before?

[sfi]

It looks like both the A and B lines for four tricks rely on Axx onside. Once you win the first trick offside the lines are already doomed and it doesn't look for an alternative way to make those tricks. It looks odd, but isn't really out of line for the purpose of the program.

[smerriman]

Well, they're also marked as MP-best; surely the purpose of the program is to tell you what line to take based on each possible result of earlier tricks.

Is it that the actual best line happens to be one of the ones that it throws out prior to showing you the results? You'd think it would be able to retain the MP-best line at least, but that's all I can think of..

[smerriman]

For reference, I figured out what was going wrong. The optimal defense (at least according to Suitplay) is for East to duck the first round, so Jxx - Axx is never counted as a winning position. So if East wins the Ace you have to play low on the second round to cover East having both A or AJ stiff.

Whether or not that's how you'd treat it in real life is an interesting question I may explore further..