[Chamaco]

I was kibbing a friend, and the following trump suit was dealt:

98654

AT32

Out of curiosity about the best chances, I fed it into Suitplay and was surprised of the theoretically best line....

[han]

Spoiler

Play low to hand and stick in the ten when east follows low. This cannot possibly cost, but picks up KQJx by east for only 2 losers.

[sceptic]

play A then one other and hope for 2/2 split, I think 51% success rate (but what do I know

[Chamaco]

Suitplay provides as only solution (no other line is even considered) the following (see hidden text)

Spoiler

low to the 9, and, if everyone follows, cash Ace next.
I found it surprising (or, at least, counter-intuitive... does this word exist in english ? ) that low to the 9 had a higher % than a first round finesse to the Ten.

[42]

Quote

...counter-intuitive...

Use "male"

[Free]

Agree with Jlall here, 3-1 or 2-2 doesn't matter, and there's only one 4-0 split we can 'handle', which is KQJx with RHO. So if you check the ♠s first, or finesse first doesn't make any difference.

The first trick actually doesn't make any difference, so suitplay could show about 10 lines of play which all do the same thing. This is probably some kind of protection against too many lines of play built in suitplay. Just test it for yourself: give a hand AKQJT and another 432, suitplay gives only 1 line, where ANY possibility gives us 5 tricks.

[Chamaco]

Free, on Sep 11 2005, 10:23 PM, said:

Agree with Jlall here, 3-1 or 2-2 doesn't matter, and there's only one 4-0 split we can 'handle', which is KQJx with RHO.  So if you check the ♠s first, or finesse first doesn't make any difference.

The first trick actually doesn't make any difference, so suitplay could show about 10 lines of play which all do the same thing.  This is probably some kind of protection against too many lines of play built in suitplay.  Just test it for yourself: give a hand AKQJT and another 432, suitplay gives only 1 line, where ANY possibility gives us 5 tricks.

Usually, when there are 2 or more lines offering the same %, Suitplay mentions them all, not just one of them.

This is why I was puzzled.

I agree with the many players that say "Do not use suitplay (or GIB), use your head", nonetheless, when I do see something anti-intuitive suggested by these "bot-programs", I try to figure out whether I am missing out something.

[han]

You are not missing anything, the two lines are equivalent. Running the 9 is a third possibility.

[Stephen Tu]

Quote

Usually, when there are 2 or more lines offering the same %, Suitplay mentions them all, not just one of them.

Perhaps it only differentiates between lines offering same % when they they take different tricks on different layouts.

Although low to the ten might draw a very stupid error, I do have to point out that on some auctions (say, south opened 1nt, partner transferred to spades & passed), playing low to the 9 does have this slight advantage of giving West a legitimate problem with KQJx -- does partner have the stiff ace?

Quote

I agree with the many players that say "Do not use suitplay (or GIB), use your head"

I think the right idea is "use your head, but double-check with the computer". Human minds are more fallible. On some complex combinations you will often just be wrong, because you forget a combination, make an arithmetic mistake adding the percentages, or missed a defensive carding tactic. Think of a line, think why you are doing this, then see if suitplay agrees. If it doesn't agree, figure out why and you can gain some insight. Sometimes the program will be wrong because of psychological factors, depending on what is visible in dummy (sometimes optimal defense against one combination is not likely to happen because declarer could hold something else).

I feel that it is rather silly to advocate abstaining from using the progam altogether, despite what a certain world-class player thinks. It's good to practice hand analysis to learn the technique & understand what you should be thinking about, but once you have done it by hand enough to know what you are doing it's a waste of time, time better spent by studying 10x more combinations with computer-aided analysis. Scientists & mathematicians do not abstain from using calculators & computers. At some point you just don't gain anything by forcing yourself to write out all layouts by hand vs. just having the computer generate them for you before you start figuring out which lines work on which layout, and letting the computer add up the totals. (Pavlicek's card-combo program).

It is important to look at the output of layouts & see what layouts are being catered to, why the line is correct, rather than just taking one quick look at the answer & being done with it. You want to think about how things would change if certain spot cards were missing/interchanged or if the bidding would make some layouts more or less likely. You need to think about what the correct defensive falsecarding strategy is on some layouts.

[pigpenz]

good idea is to know what we are playing for the max amt of winners here or some other number that has alot to do with it