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Mastering Backgammon (38)
2007-07-23
Bill Robertie
Bill Robertie
38. More About Proto-Backgames
Some time ago I wrote a column about proto-backgames, those positions where one or both sides had a number of men back, but the character of the game had not yet crystallized. While a backgame was one possible outcome, there were other directions the position could still take. Both sides needed to be extremely accurate in their checker play, so as not to close off other variations prematurely.
One of our readers, Christian Munk-Christiansen from Denmark, has submitted the following proto-backgame position for analysis.
Position 1: Money game. Black on roll. Black to play 3-1.
Black
• He can make a third backgame point with Bar/22 23/22 and settle into a pretty well-defined backgame while allowing White to clean up his blots.
• Or, he can try to go forward with Bar/24* 21/18*, hitting two blots and taking aim at the other White blots scattered around the board.
Both plays are superficially inviting. Backgames with three points in the opponent's home board are rare but very strong. They're especially strong if the opponent's ace-point is not one of the backgame points. This assures that the opponent will always be able to play his numbers (often burying checkers on the ace-point), so timing these games will be easier than usual. In this position, White may also be forced to eventually leave a blot on an outer-board point before he's borne off any checkers, raising the possibility of a gammon for Black.
Can Black time his game if he goes directly into a backgame? Probably, although it's not certain. After playing Bar/22 23/22, he trails in the pip count by 83 pips, which is usually plenty of timing for a backgame. However, to get the advantage of all that timing, he'll have to break the 21-point sometime in the future. That's not a disaster, but it does mean that his game isn't quite as strong as it looks.
What about the double-hit?
At first glance, the play looks good. Two White checkers on the bar, plus two more blots to collect later. But Black's home board isn't very strong, and may not become strong for some time. Black can collect checkers, but White will bring them in quickly. After three or four turns, White will have some men in Black's home board, but Black's position still won't be threatening. At best, Black may have an even game. At worst, Black will still be in some sort of backgame, but with timing that's much worse than the current position.
The right play, by a wide margin, is to make the 22-point. The breakout play with the double-hit just isn't strong enough because of the weakness of Black's home board.
What would make a breakout play correct? Take a look at the next diagram:
Position 2: Money game. Black on roll. Black to play 3-1.
Now Black has a real home board, and this changes the evaluation completely. Now the double-hit is correct, and by a wide margin. The powerful combination of the 4, 5, and 6-points gives Black the chance to not only collect a few blots, but also keep them contained while he brings out his back checkers. The double-hit in Position 2 actually makes Black a small equity favorite in the game, with slightly better gammon chances than White!
Position 3: Money game. Black on roll. Black to play 3-1.
Position 3 shows a more complex variation. Black has a strong home board as in Position 2, but White has cleaned up some of his blots. As in Position 1, the right idea is now the third backgame point: Bar/22 23/22. Hitting two blots with no additional targets will only allow Black to upgrade his potential backgame points, but with less timing for any true backgame variations.
The general rule that emerges from these positions is that a third point in the opponent's inner board is a very big asset, and will generally be the default play in the absence of some unusual circumstances.
