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Let me bitch some more about something diff.

Posted By: Stick
Date: Saturday, 25 October 2008, at 6:18 p.m.

Let me do the politically correct thing and state I'm not meaning to pick on one person or one 'printing' (be it newsletter, online site/article, book, w/e). I will not mention where I got what problems from because again, not the point, it happens way too often in my opinion and there's no one isolated source. If you know where they came from, fine, don't mention it.

My problem this week? Lackluster backgammon literature. These people are being paid to write and I see problems where they have the wrong answer or they did a Steve Sax 72 game rollout and called it a day (I care enough to pick on the very best). A couple of recent examples that pushed me over the top. There are many many many more examples I could look up but I'm going to use what I have in front of me.

The score (after 0 games) is: gnubg 13, user 9 (match to 15 points)

Move number 5: user on roll, cube decision?

gnubg	95
user	108
Position ID: trsDCEC02x4AIA Match ID: cAngAdAASAAA

Cube decision
Rollout cubeless equity		+0.449	(Money: +0.441)
Cubeful equities:
1.	Double, pass	+1.000
2.	Double, take	+1.013	+0.013
3.	No double	+0.742	-0.258
Proper cube action:		Double, pass
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Centered 1-cube 0.707 0.109 0.003 - 0.293 0.079 0.005 +0.449 +0.742 Standard error 0.001 0.001 0.000 - 0.001 0.003 0.001 0.003 0.004 Player gnubg owns 2-cube 0.714 0.114 0.003 - 0.286 0.102 0.013 +1.013 +1.013 Standard error 0.002 0.002 0.000 - 0.002 0.005 0.002 0.008 0.008
Full cubeful rollout with var.redn.
1297 games, Mersenne Twister dice gen. with seed 808445695 and quasi-random dice
Play: 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 12 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

In the example above the player in question (user) did not arrive at this position because he blundered on the move before. White fanned in the actual match and Blue cubed him out. If Blue had made the correct play as shown above White still would have fanned and we'd have arrived at this position.

The article says in short that had Blue made the correct play he would no longer have a cube out so the blunder in fact generated more quick wins. I'm a Knight who says NI.

Money Game
White on roll. Cube Action?

64
86

Cube decision
Rollout cubeless equity		-0.110
Cubeful equities:
1.	No double	+0.032
2.	Double, pass	+1.000	+0.968
3.	Double, take	-0.630	-0.662
Proper cube action:		No redouble, beaver (40.6%)
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Player gnubg owns 4-cube 0.466 0.004 0.000 - 0.534 0.046 0.001 -0.110 +0.032 Standard error 0.002 0.002 0.000 - 0.002 0.003 0.000 0.004 0.006 Player user owns 8-cube 0.467 0.004 0.000 - 0.533 0.046 0.001 -0.219 -0.630 Standard error 0.002 0.002 0.000 - 0.002 0.003 0.000 0.009 0.025
Full cubeful rollout with var.redn.
216 games, Mersenne Twister dice gen. with seed 807964625 and quasi-random dice
Play: 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 12 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

Is the following statement true or false in the above example: White is only a tiny underdog owning the cube.

gnubg	142
user	133
Position ID: cLc1AGBsuyEAIw Match ID: UQkAAAAAAAAA

Cube decision
Rollout cubeless equity		+0.804
Cubeful equities:
1.	No double	+1.015
2.	Double, take	+1.369	+0.355
3.	Double, pass	+1.000	-0.015
Proper cube action:		Too good to redouble, pass (3.9%)
Rollout details
Win W g W bg Lose L g L bg Cubeless Cubeful Player user owns 2-cube 0.697 0.448 0.025 - 0.303 0.061 0.002 +0.804 +1.015 Standard error 0.001 0.001 0.001 - 0.001 0.001 0.000 0.003 0.005 Player gnubg owns 4-cube 0.700 0.459 0.023 - 0.300 0.058 0.003 +1.642 +1.369 Standard error 0.001 0.001 0.001 - 0.001 0.001 0.000 0.007 0.010
Full cubeful rollout with var.redn.
3363 games, Mersenne Twister dice gen. with seed 807736041 and quasi-random dice
Play: 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 12 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]

The last example comes from a quiz where it asks Blue's proper cube action. The answer given is RD/P, what do you think?

Maybe I'm nitpicking, tough shit, in today's computer age I expect you if you're going to write an article that is being paid for by its readers to spend more than the 1/2 a day I spent with one core on these problems. I will cover my own ass noting that possibly the writers used Snowie and came up with different answers, maybe they used a different MET, maybe different rollout settings, all would be an explanation to why they're inaccurate.

Those are merely excuses to me though. If you used diff. rollout settings I can only imagine they're weaker and that's why you got the obscure results. I rarely see rollout results for money games where GNU & Snowie differ by hardly anything at all, esp. in such simple positions. The MET theory is only applicable to problem #1.

Also, if they did get diff. answers for one of the above excuses I highly doubt their answers were definitive so I'd avoid making such statements in a written article or posting a quiz problem where the answer is borderline.

My complaint staff is not limiting itself to one medium, I see the problem across the board. Is there any good excuse for such laziness?

Stick

Messages In This Thread

• Let me bitch some more about something diff.
  Stick -- Saturday, 25 October 2008, at 6:18 p.m.
  • Let me bitch some more about something diff.
    Bob Koca -- Saturday, 25 October 2008, at 6:46 p.m.
    • Pos. 1, Blue's previous turn
      Chuck Bower -- Saturday, 25 October 2008, at 7:09 p.m.
    • Let me bitch some more about something diff.
      Stick -- Saturday, 25 October 2008, at 7:10 p.m.
  • Welcome to the club
    Chuck Bower -- Saturday, 25 October 2008, at 7:15 p.m.
    • Welcome to the club
      Stick -- Saturday, 25 October 2008, at 7:34 p.m.
      • Welcome to the club
        Chuck Bower -- Saturday, 25 October 2008, at 7:50 p.m.
      • Welcome to the club
        Matt Cohn-Geier -- Sunday, 26 October 2008, at 3:28 a.m.