How would you compare humans with computer programs when it comes to playing chess or bridge?
In chess the positions of the pieces are always known. It is a pure computational exercise. This explains why machines have done so well against even the top grandmasters.
In bridge, though, there is incomplete information: the unseen cards. This makes it a very difficult programming exercise and is why, in my opinion, humans will always play better than machines.
As an example, look at the diagramed deal, from the final of the world computer championship in Bali, Indonesia, last month, played between the computers Jack and WBridge5.
One South was in six hearts and the opposing North was in six no-trump. In each case, the opening lead was a diamond. How should the declarers have played?
After North opened one club, both computer programs responded two hearts, a strong jump shift. The rest of the auctions were strange.
I treat a strong jump shift as showing one of two hand types: an excellent one-suiter, or a two-suiter with length in both responder’s suit and opener’s suit. (Some pairs also allow a big balanced hand.) In my method, the opener usually makes an economical rebid to find out the responder’s hand type. But opener may rebid in a side suit headed by at least two of the top three honors — hence North’s three-diamond rebid.
(A two-no-trump rebid, to leave responder space to show club support if he has it, would be sensible also. I would not rebid two spades, where responder cannot have four-card length, because the suit is too weak.)
After that, there are several possible routes to six hearts. Mine saves space.
The correct play in six hearts is to win the first trick in the dummy and play a trump. When East puts up the ten, declarer should finesse his jack, in case East has all four trumps. The finesse loses, but South has 12 tricks, discarding the spade five on a high club in the dummy.
The computer program won the first trump trick with the king, which did not cost here. But the finesse is the correct play, because hearts 4-0 was much more likely than diamonds 7-1 with West’s being able to win the second trick and give East a diamond ruff.
In six no-trump, North should similarly play on hearts to collect 12 easy tricks: one spade, seven hearts, two diamonds and two clubs. (Even a spade lead would not be fatal, because declarer can finesse and take three spades, two hearts, two diamonds and five clubs.)
The computer program took the first trick with the diamond ace and ran the spade queen. West won with the king and led back its highest diamond.
Now North, with its communications in tatters, went down three.