|
At the Texas Backgammon Championships this weekend, Victor Ashkenazi demonstrated the kind of verve under pressure that has earned him a place among the Giants of Backgammon. Victor’s wildly imaginative play was way beyond me. I was flabbergasted when I saw him play X (Hit and split) = 23/17 7/4* in the position above.
What is he doing, I wondered. With the match on the line in an uphill battle, his only asset seems to be his 4-point block. Why sacrifice it in an apparently suicidal attack that leaves return shots with any 3 or 4, plus 21, 22, 52, and 61? That totals to 4 blots and 27 shots! Why not play the very natural-looking R (Run) = 23/14, which leaves only 1 blot and 14 shots? And, above all, why not trust his block?
The answer, it turns out, is not because X is the gammon-go play (although it is). The reason is because X is the DMP play. At GG, the lure of winning a gammon combined with the freedom to lose one is what distorts play compared to normal match scores. In this, the Crawford game, it is the fact that losing a gammon will not cost any more than losing the game that is primarily driving the decision. Victor can afford to leave all those blots and shots because his gammon cost is zero. When gammons losses count, as in unlimited games, X falls to only 8th best. At gammon-save, it does even worse, plummeting to 12th place in an XGR++ eval.
Beyond that, I am still puzzled. Why is such open play best? What are the mechanics of this? Are Victor’s chances so low that he must hang his hat on the 9 numbers where he is missed?
I would love to hear your thoughts on this. Below are rollouts for the original position (GG), plus unlimited games and DMP.
By the way, in the follow up, Victor was rewarded when Petko Kostadinov rolled 55, dancing against a 2-point board, and then Victor poured out a 53, instantly completing a 4-point board. Sadly for Victor, his advantage quickly dissipated a couple of turns later when Petko rolled a lucky 11 from the bar. Hitting twice, Petko sent a 3rd and 4th checker behind his 5-point semi-prime. Despite a late hit by Ashkenazi from his anchor, the game and match went to fellow backgammon giant Petko Kostadinov.
Mike |
