[chasetb]

I have become tired of putting down all the mundane mistakes GIB makes, because it seems like enough isn't being done. In an express tourney, why doesn't GIB just return the lead? People DO make mistakes.

http://tinyurl.com/6yv5rde

[barmar]

Probably because it expected South to have more spades, for its jump to slam with no support from partner, so it 's not likely to have so many clubs. So the lead looks more like a doubleton than singleton.

[cloa513]

If its doubleton then there's no defence so why not return a club.

[barmar]

When GIB sees a short suit in dummy, it often leads trumps to prevent declarer from ruffing.

GIB isn't programmed with the logic "If there's only one layout where you can set the contract, assume that layout." It deals out a bunch of hands that are consistent with the auction, and performs a double-dummy analysis of each of them to find the plays that results in the most tricks. Then it chooses the play that shows up the most. This algorithm is also why it doesn't take safety plays when declaring.

This obviously isn't the way to play optimally, but this is how GIB is written. It would presumably take a major redesign to fix it.

[manudude03]

Maybe not, it would slow the bots down, but how about after x simulations, if there are 2 plays or calls which have identical results, run another x simulations and repeat again if necessary. If after 3x simulations there is still no difference, then allow it to pick one at random.