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Woolsey-Jones Rollout by Taper_Mike | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
eXtreme Gammon Version: 2.03
Woolsey-Jones, Problem 80After giving a first-class explanation why lifting the 7pt is better than breaking the 8pt, Kit missed the obvious duplication of 2s, and the somewhat less obvious problem playing a roll of 65 presents for Blue after he advances to the 13pt. Kit’s move is third best. The original play made by Tami Jones comes in last in the rollout. For a book that was written so late in the bot era, and by one of the best authors ever, it is surprising that so many of its solutions are now being challenged by XG rollouts. Igor Erovenko has been doing all the sleuthing:
As Igor gets deeper into the book, more errors may be found. I have speculated that rollouts by Snowie are the cause of the trouble. The positions in Understanding Backgammon are all taken from the match play of Tami Jones as rolled out by Snowie. Unfortunately, Snowie does not perform rollouts according to match score. Someone who has more experience with Snowie than I do may be able to explain this better, but my understanding is that Snowie applies a formula to “correct” its unlimited game result according to the actual match score. This is known to distort some of the equities. Then, even though Tami’s original rollouts were made at score, for the book, all the problems were presented in unlimited games. The book’s Introduction does not make clear whether new rollouts were made for unlimited games. So, one explanation for the errors is that Kit took Tami’s match-play rollouts as gospel, trusted that they were accurate in unlimited games, and then supplied an analysis to go with them. Be forewarned. As plausible as this explanation may be, it is only speculation. Mike |