Humans versus Jack (2)Computer Bridge 2; World Champion Jack in Action(published in Dutch Bridge Magazine IMP July/August 2005)To gauge the playing strength of Jack, we matched him against seven strong Dutch pairs. This instalment covers the first three matches. To get quick results we decided to play 'Instant IMPS.' The boards had been played about five years ago in the First Division and none of the players had seen them before. We selected complete sets and played them in the order in which they had been played originally. Each pair of human chose which of four sets of 28 boards to play and whether to sit North-South or East-West. As each human pair played different boards, a fair comparison among human pairs was not possible, but this arrangement avoided the dullness of having the same deals played seven times. The playing conditions were as normal as possible. Martin Pattenier operated the computer while Hans Kuijf and I bid and played for Jack by following the instructions Martin read from the screen. Before the first match the Jack team was a bit nervous. Were we too optimistic to challenge the best of the Netherlands' pairs? What if all of them beat Jack decisively? After the first three matches we gave a sigh of relief. Two wins and one small loss. The experiment was a big success already! In the match against Hanneke Kreijns & Just vd Kam, Jack's wide-range preempts proved effective and had a major influence.
After 4 A few boards later Jack opened another pre-empt. This time EW were a bit more cautious.
This time West's caution missed a laydown 4 So the first match gave a nice feeling. But what about Janssen & Top, the reigning
Dutch Pairs champion? This time Jack's adventurous preemption ended less fortunately.
With both sides vulnerable, Jack opened 3 From the match against Eric Janssen and Jeroen Top:
The bidding requires some explanation. Only a few days earlier Janssen&Top
started playing the Bocchi-Duboin transfers after an overcall, so
2 JackW's 3 Jan van Cleeff and Vincent Kroes soon noticed that Jack played a lot better then they had expected. About halfway through the match, van Cleeff had to play a contract that could not be made. Van Cleeff kept thinking and thinking. Meanwhile, Kroes glanced at the screen, where a double-dummy analyzer showed 'two off,' so he made a little joke: "Jack says you can make it!" Van Cleeff plunged into deep thought. After a while, Kroes felt pity and rescued him. Playing well is not always an advantage. Van Cleeff & Kroes cleverly gave Jack an extra option and he took the best technical line. No good! From the match against Jan van Cleeff and Vincent Kroes:
Some explanation:
2 Against 4
Seeing all four hands you might wonder how Jack could go wrong. The ace of hearts and a heart, or a low heart towards dummy first would
succeed. Everything works. But watch out! Double-dummy analysis is a well- known
pitfall. Analysing objectively is not so easy, at least for humans, when all
the cards are visible. However, Jack always plays according to the probabilities.
With this holding he 'knows' the best way to play hearts is to finesse through
East twice. That is why he kept two diamond entries to dummy. Without a blink
he crossed to the The chosen line works if the The results of the first three matches:
Next time Jack plays against Paul Felten & Eric van Valen, Ton Bakkeren & Huub Bertens and Vincent Ramondt & Berry Westra. Will he survive? Wim Heemskerk | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||