October 9th 2023 – Paul Segal (white) V Chris White (black)

White has rolled 11

There was quite a discussion about this. The obvious next move appears to be 23/22 3/2* but then what? The passing hit 2/1 5/4? Or maybe 6/4 leaving a blot on 2?

What about starting with 5/2* 3/2 creating a 6 point prime but a likely problem getting those back checkers out?

Extreme gammon gave this analysis

The #1 option is to close your home board. But the top 3 options are all so close it could be argued they are all the right move.

From Simon Woodhead: I would play 23/22 first. Then 6/4 3/2*. My (incorrect) thinking is that a) we must get the back checker up to the edge and make an anchor, and b) we must hit to prevent black improving and/or escaping. The score should make a difference here! 4-3 means Black can win the match with a gammon so they are on Gammon Go. If the score is 4-2, White can afford to lose a gammon.

Pick and pass is an error because Black can play and if they roll a 2 can then escape with 5s/6s or even improve with 5-4, 5-5. Leaving the blot on the 2pt gives cover possibilities (when not hit) which may buy time to escape. If Black hits, we have the 22pt anchor and if the score is 4-2 gammons don’t matter anyway.

Why is 23/22 wrong? Why does XG prefer the close-out? It’s because Black has the timing and we have none. If we don’t escape in the next roll or two, we crunch and it’s game over. 23/22 looks right but doesn’t actually help – we either escape one checker very soon or we die. PoH means that if we do escape, we have the time to roll another 1 plus a 6, all while Black remains closed out. Kudos to Vince for seeing this 🙂