Finding the bot play here isn't so easy, but there is an easier
question that I still see lots of players getting wrong: What's
your game plan? X is way behind in the pip count. O has big
stacks, and X already has a prime forming. So the answer is:
X's game plan is to prime. O, on the other hand, prefers to
race or attack. In particular, any play involving 24/22 or
24/21 *is not even a candidate*. You should not even think
about touching those back checkers. What do you think you're
accomplishing? You're not trying to race. You're not in grave
danger of getting primed. Playing 24/22 or 24/21 just gives O
a chance to unload those stacks on your head. This theme comes
up over and over again, sometimes as early as the third roll of
a game, such as if you open with 8/5 6/5 and your opponent rolls
55 and plays 13/3(2). If this happens, what's your game plan?
If you didn't immediately say that you want to prime then I'll
come over to your house and beat you over the head with a foam
bat until you say it. And if you then roll 32 and split then
you deserve to lose.
Even after you decide that you want to prime, though, there
are still a few options. You can give yourself partial credit
for 13/10 6/4 because that's at least a reasonable strategic
idea---making 5 out of 6 points and slotting the front of the
prime. However, the bot play is 7/4 6/4. This is similar to
the first problem in this year's Othello quiz, although in one
way it's trickier because O's sixes aren't duplicated. But it
does make the strongest bid for a good prime. Leaving a double
shot is bold, but Magriel's criteria all point to a bold play.
1. Rollout¹ 7/4 6/4 eq:+0.121
Player: 60.76% (G:19.77% B:1.38%)
Opponent: 39.24% (G:14.95% B:1.71%)
Confidence: ±0.010 (+0.111..+0.132) - [100.0%]
2. Rollout¹ 13/10 6/4 eq:+0.073 (-0.048)
Player: 60.48% (G:15.99% B:0.88%)
Opponent: 39.52% (G:14.69% B:1.64%)
Confidence: ±0.011 (+0.062..+0.084) - [0.0%]
3. Rollout¹ 10/7 6/4 eq:+0.024 (-0.097)
Player: 57.74% (G:16.42% B:0.92%)
Opponent: 42.26% (G:14.16% B:1.25%)
Confidence: ±0.013 (+0.011..+0.037) - [0.0%]
4. Rollout¹ 6/1* eq:-0.012 (-0.133)
Player: 55.48% (G:20.20% B:1.73%)
Opponent: 44.52% (G:16.15% B:1.72%)
Confidence: ±0.012 (-0.024..+0.001) - [0.0%]
5. Rollout¹ 13/11 13/10 eq:-0.016 (-0.137)
Player: 56.58% (G:15.47% B:0.77%)
Opponent: 43.42% (G:13.92% B:1.05%)
Confidence: ±0.011 (-0.026..-0.005) - [0.0%]
6. Rollout¹ 10/5 eq:-0.025 (-0.146)
Player: 55.69% (G:16.04% B:0.81%)
Opponent: 44.31% (G:13.18% B:0.95%)
Confidence: ±0.010 (-0.035..-0.014) - [0.0%]
¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
eXtreme Gammon Version: 2.19.207.pre-release
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Tim Chow