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| XGID=aABBCCBA-----A------abc-b-:2:-1:1:61:0:0:0:0:10 | |||||
| Blue to play 61 | |||||
If Blue plays n = 13/7 4/3, leaving a blot on the 1pt, and White fails to hit, Blue will have all the even numbers to use as covers. 36 out of 36 rolls play safely, and all but 55 give Blue a closed board.
If White rolls a 1 to hit, then he will need a 1, 2, or 4 to go with it. Otherwise he will leave a blot, and Blue will get a shot. From the bar, Blue does not have any entering numbers that force him to crack.
By themselves, these considerations indicate that there is little risk in trying to pick up a second blot. What they ignore, however, is the equity Blue loses when he lets his spares migrate down to the lower points in his board. When that happens, he will often be forced to open up sooner than he would otherwise.
If Blue puts two checkers on his 7pt now, and White fails to hit, where are those checkers going to go on subsequent moves? In most variations, neither one lands on the 6pt, the place Blue would most like to put one.
XG and GnuBg have taught me to play this a bit more conservatively than I used to. It is sort of like giving up the midpoint when you hold a high anchor in a holding game. The bots typically abandon the midpoint one turn sooner than they absolutely have to. The same is true here. Covering the ace point one turn sooner than you are forced to is often the best way to go.
Therefore, I would play C = 13/12 7/1. All rolls play safely next turn, and Blue has an excellent chance land a checker on the 6pt during the remainder of the bear-in.
It would be interesting to see how this position changes when you remove another checker or three from White’s side of the board. With 7, 8, or 9 checkers off, the incentive to go for a second checker will rise.
Mike