Looking at http://www.bgonline.org/forums/webbbs_config.pl?read=34836 one more time.
The score (after 0 games) is: White 2, Blue 4 (match to 5 points, post-Crawford play)
Move number 6: Blue to play 11
| White | 102 |
|---|---|
| |
| Blue | 49 |
Position ID: t7kBIBLMAEQAAA Match ID: UYmkACAAIAAA | |
It was established that 18/17 15/14 3/2*(2) is clearly best. This play leaves the least amount of return shots from the bar. However, perhaps not so obviously, this play is also clearly best when White doesn't roll a hit from the bar. Why?
First of all, it forces White to play. Although Blue gains quite a bit when White gets stuck on the bar with one or two checkers, he loses quite a bit when White sits on a low point and waits for Blue to come to him. If Blue shifts off only the back checker then White is forced forward with basically all of his aces (he can only hang back safely with 21) and so will be sitting on at least the 22 point, probably higher, or else leave a direct shot in the outfield. If Blue double shifts White can come in on the ace point and be sitting deep in his board for awhile.
Second, it may not look like it, but it turns out that the cleanup is significantly easier after 18/17 3/2*(2). Blue is pretty safely home if he can safety a checker. White would need to hit the remaining checker and then contain it which is easier said than done with the open 4 point. If Blue can manage to get home with both then White is in pretty dire shape as pretty much the only way he can win at that point is to close out two blots. 18/17 15/14 3/2*(2) gives the most rolls to safety at least one of the Blue checkers.
After that play, Blue has 9s, 12s, and 15s (9 numbers) to safety at least one blot, though 63 is duplicated. 66 safeties both of them. After any other play, 66 leaves a double direct at two blots.
After the double shift, Blue has 11s and 16s (3 numbers) to safety a blot.
After 18/17 15/14 5/4*(2), Blue has 10s & 11s (5 numbers) to safety.
After 18/16 3/2*(2), Blue has 10s & 11s (5 numbers) to safety, but 11s are duplicated.
There are also 8 rolls to make an outside point after either play (since the checkers are 3 pips apart in any case). 18/16 gives 10 rolls to make an outside point but the two extra are the duplicated 11s.
The most numbers to safety is good and in particular the big swing on 66 going from being almost gin to leaving a double direct at two blots is quite big. In addition to the fact that 18/17 15/14 3/2*(2) is safer, the hitting sets from the bar are still big. I am not sure if there are any visual cues one can use to see that the cleanup is easier after 18/17 15/14 3/2*(2), I don't really know of any, and I would have probably gotten this one wrong to be honest. The only way I would have gotten it right is if I judged the hitting sets from the bar enough to swing it; I would certainly not have thought that 18/17 15/14 3/2*(2) was safer without going through the rolls.