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Joined: Sun Oct 24, 2010 8:32 pm
Years playing backgammon: 20+ Learned to play on fibs.com playing bots and review with gnubg analysis FIBS rating 1750-1850
Location: USA

Huge Blunder 4X oops..

So I managed to make a .400 blunder and even when reviewing the move, I could not see why it was such a big mistake. That is unsettling. What ?? :? .400 error? Must be a bot mistake. Rollout :oops: yep 4X blunder. Here it is
1.png
1. Cubeful 3-ply 20/13 Eq.: +0.275
0.638 0.002 0.000 - 0.362 0.001 0.000
3-ply cubeful prune [grandmaster]
2. Cubeful 3-ply 7/1 6/5 Eq.: -0.160 ( -0.435)
0.420 0.159 0.003 - 0.580 0.118 0.002
3-ply cubeful prune [grandmaster]

Playing White, 1 pt match, I am slightly ahead in the race (+6) and I roll 6-1 which allows me to safety the runner but I left it back there and moved 7/1 6/5.
BAM 4X blunder.

So in what situation would 7/1 6/5 be the correct play?
Here it is. When you are far behind in the race, you stay back.
But even running would only be a .05 error and slightly reducing the race advantage for Red makes running the correct play
2.png
1. Cubeful 2-ply 7/1 6/5 Eq.: -0.561
0.220 0.030 0.000 - 0.780 0.136 0.002
2-ply cubeful
2. Cubeful 2-ply 7/6 7/1 Eq.: -0.602 ( -0.041)
0.199 0.021 0.000 - 0.801 0.122 0.001
2-ply cubeful
3. Cubeful 2-ply 20/13 Eq.: -0.617 ( -0.056)
0.191 0.001 0.000 - 0.809 0.001 0.000
2-ply cubeful


So there you have it. :D Keep track of the race otherwise you could end up with a hefty embarrassing blunder that kills your winning chances.
I did end up winning this match in spite of the blunder so always review even when you win.
Full match gnubg sgf file is attached
Attachments
201802190357_tetraHydro_GreedyG.zip
(18.8 KiB) Downloaded 803 times
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