We had a great afternoon of backgammon again today. Nine players showed up to play, and so I had to make the difficult decision to cut one player. Makena drew the short straw, but gamely stuck around to watch and learn, and got into a post-tournament match and some chouette action. Chris (yes that Chris) showed up to watch as well. Pete and Molly came down from Seattle, Mark S came up from Drain, and Martin, Arto, Bryan, Michael and I rounded it out. All in all a pretty good showing!
In the first round, Martin won over Pete, Arto over Molly, Mark S over Bryan, and I won over Michael. I didn’t get all the scores, but my sense was they were all 11-10/11-9 kind of victories – closely fought matches.
I took an early lead against Michael, and in our 4th or 5th game, he offered me the following cube, when I was leading 6-1 in our match to 11:
We’re bearing off to the left, so I have three checkers back and a couple of blots on my home board, just to orient you. The theory I like to think through for doubles is “Position, Race, and Threat”. Here, the position is slightly in his favor – we both have two point boards, but he has the more advanced anchor and only two checkers back. The race is pretty even – he’s up 134 to 135 and on roll, but that’s not a major disadvantage. Threat is also pretty modest. So he’s got a slight edge on all three but not a big edge on any of them. For money, it’s not even a double. But being behind in the match, he figured it was a fair double. After some thought, I took. What do you think?
XG says that this is in fact not quite a double, and a clear take. It’s a -0.057 error to double. Curiously, if he held the cube, it’s a good redouble! Match score must play into it somehow, but I can’t figure it out. Anyway, he doubled, I took, and he proceeded to win by a gammon. I take consolation that I correctly took the cube.
Second round, I faced off against Mark S and Arto sat down against Martin. In our first game, I reached this classic end-game cube decision point:
I had doubled earlier in the bearoff, and a couple of good rolls left Mark S on roll with three checkers to go to my two. He redoubled. This is one you can really think through over the board. He clears his board on this roll with double 3’s or better – 4 rolls. So 32/36, which is about 89%, I get to roll. At that point, I clear with double 2’s through double 6’s, plus any combination of rolls better than 4 (4-5, 4-6, 5-6). That’s 11/36 rolls. 32/36 * 11/36 = 352/1296, which is better than a quarter, so it’s a redouble/take. It’s fun (to me, at least) to get these kind of positions that allow for a mathematical decision. Anyway, he rolled something like a 5-1, I rolled something like a 5-1, and he won. A couple of games later, he won a doubled gammon, and I ultimately lost the match 11-3 or so.
In the meantime, Arto was losing a much closer match to Martin, and we were getting close to finishing the tournament. Martin and Mark S faced off, negotiated a hedge, and went to. I got into a chouette with Bryan, Molly, Pete, and Makena. The tournament wrapped up an hour or so later with Mark S nosing out Martin, but the chouette went about 3 hours more.
A big thanks to everyone for coming out, it was a blast, and I will do another one before too much longer.