Position 33, page 55
From Better Backgammon, by Tim Holland

White to play 2-1.

The correct play is to move one man from White’s bar point to White’s 5 point. By giving up your prime, you now force Black to break your 1 point with any roll that contains a 6 (except 5 and 6). This is something he desperately does not want to do since this would give you the opportunity to make your 1 point. Another reason for giving up your bar point rather than your 8 point is that if you are forced to leave a blot in your attempt to enter your remaining man from your 8 point, your opponent will have men on only one point that is in direct range (6 or less pips away) to hit with. If you choose to break your 8 point and subsequently are forced to leave a blot on your bar point, your opponent would have men on two points that would be bearing directly on this blot (therefore increasing his chances of hitting).

If you’re asking why break your prime at all, the answer is this: on your next roll you must do so in any case (except with the roll of double 6s). By placing all of your odd men on the 3 point you will have increased the probability of leaving blots in the attempt to enter your remaining men. By maintaining the prime, you also prevent Black from playing 6s, which, as you can see, are very bad for him. It’s true that by breaking your bar point you allow him to escape with a five, but a five he can handle in his home board anyway.

7/5, 7/6  *
8/7, 8/6 x
XG logo
Tom Keith 2013 
Money play
Black owns 2-cube
White rolls 2-1

1296 games with VR
Checker play: 3-ply
Cube play: XG Roller

2-1: Game BG   Equity
1 8/7, 8/6 W
+0.7621 x 
2 7/6, 7/5 W
+0.7231 (0.0390)  *

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No. 32, page 53
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No. 34, page 56

List of Positions from Better Backgammon

Better Backgammon (1974), by Tim Holland

Backgammon Galore : Books