Thursday, 16 June 2011
Double or Too Good?
Here's where we left it, Blue on roll trailing 5-away, 7-away and White on the bar. This is a very strong double and a clear pass. In round numbers, Blue can expect 71% wins from here, including 29 gammons. Blue has a lot going for him, viz. one white checker on the bar, shooting at a second blot, a better anchor and 9 checkers lined up to make the vital 5pt. Should Blue indeed play on for the gammon? It's possible, it's a very close decision, with Blue gaining minutely in theory if he plays on. In practice though, he will have to play very well to achieve the theoretical equity and he will also have to recognise the exact point when he is no longer too good and double if his game deteriorates a bit. This is asking a lot and I always double if I think it is close. Why? If you are wrong and they pass, at least it scores a point without having to play for it. This has to be worth a small piece of theoretical equity. Furthermore, sometimes they take and then you are in clover. White, a 1900+ player on fibs took this.
Then I rolled 3-2.
I chose making the 5pt, but that is a small error. I need to play 21/18*/16. A roll of 6-3, yes, make the 5pt and hope to pick up the blot next time, but giving up the bar to make the 5pt here is just too loose. The bar is still very important and I have three active builders to hit loose on the 5pt next turn if needed, or of course make it. I find that I often make mistakes, sometimes big ones after a double and take. Perhaps when my cube is picked up I just need to take stock a bit.
Then we got to this position.
This one comes up a lot in various guises. Do I carry on with the great escape from the back? Do I wheel anothe builder up to bear on the 3 and 2pts? It's a balancing act, comparing how easy is it to escape with how much another builder really gains. Have a think about it and we'll have another look tomorrow, when I'll show you a cute shorthand trick for counting the number of rolls that make the next point.
Until then, enjoy the game!