Game 2 Move 7 the Herd Cube Decision

[ah_clem]

We get to make another cube decision.

[ah_clem]

Spoiler

So I think I've successfully shielded my eyes from the bot results long enough to weigh in on this one.  Actually, I didn't know bot-answer to the other recent cube decisions either (and still don't) , it's just that I'd seen enough to color my opinion so I was reluctant to post anything or vote; that said, had I posted an opinion anybody who followed it blindly would be a fool - a glimpse at equity numbers coupled with a mediocre understanding of how to apply them != actionable intelligence.  Probably just the opposite.  So what follows is my opinion not based on bot results, but if it has been subtly influenced, it's been filtered to the point where you shouldn't take my word for it.  I'm just saying...

Enough navel gazing, on to my analysis:

This looks like a ace point game to me. And a well timed one at that.  A well timed ace point game leads to about 20% wins and 20% gammon losses for the holder of the ace point (i.e. Zorba)  Th usual rule is that you have to win twice as many gammons as single-point losses to play on, and here it's 1-1.  So push the cube and take the single point.


Double.

[close]

[NIHILIST]

Paul Magriel had the identical position in 1987. His analysis was also identical to yours.

Bob

[ah_clem]

Paul Magriel had the identical position in 1987. His analysis was also identical to yours.

But I'll bet he didn't spend as much time worrying about whether it was appropriate to comment because he had glimpsed some gnubg results few moves earlier.  (c:

[ah_clem]

The vote is 5-zip, and it's pretty obvious despite my channeling Hamlet over the decision.  So let's move on, and Zorba can wake up tomorrrow with a decision to make.

Next time, maybe I'll do King George: "A six!  A six! My kingdom for a six!"

[diane]

Next time, maybe I'll do King George: "A six!  A six! My kingdom for a six!"

Hey that is my tag line..."A <insert desired number here>!  A <insert desired number here>! My kingdom for a <insert desired number here>!"

Sometimes, it works, but often fibs deems my kingdom unworthy...or maybe it knows I don't actually hand it over...

[ah_clem]

rollout

Spoiler

This is marginally too good. Cubing here would not be a very big error.  Kudos to the Herd for correctly analyzing a close decision.



////////////////////////////////////////////////////////////
2-ply analysis:
Cube analysis
2-ply cubeless equity  +0.900 (Money:  +0.803)
 0.741 0.379 0.013 - 0.259 0.069 0.002
Cubeful equities:
1. No double            +1.045
2. Double, take         +1.913  ( +0.868)
3. Double, pass         +1.000  ( -0.045)
Proper cube action: Too good to double, pass (4.9%)

///////////////////////////////////////////////////////////////////////////

0-ply rollut

Rollout details:
Centered 1-cube:
 0.740 0.382 0.020 - 0.260 0.068 0.004 CL  +0.896 CF  +1.040
[0.001 0.002 0.002 - 0.001 0.001 0.001 CL   0.005 CF   0.010]
Player Zorba owns 2-cube:
 0.746 0.380 0.040 - 0.254 0.064 0.005 CL  +2.259 CF  +2.015
[0.002 0.003 0.003 - 0.002 0.001 0.001 CL   0.014 CF   0.017]
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 903967096 and quasi-random

dice
Play: 0-ply cubeful prune [expert]
Cube: 0-ply cubeful prune [expert]



1. No double            +1.040
2. Double, take         +2.015  ( +0.975)
3. Double, pass         +1.000  ( -0.040)
Proper cube action: Too good to double, pass

[close]

Apologies for the edits here...I accidentally deleted all your post instead of quoting it...but it is ok, I managed to rebuild it, even better than new - because now it has all this extra stuff at the bottom  
Diane

[diane]

rollout

Spoiler

This is marginally too good. Cubing here would not be a very big error.  Kudos to the Herd for correctly analyzing a close decision.

[close]

Spoiler

See that lone voice dissenting up there..that is me that is, also feeling this was a bit too good - and that I would rather wait and play on..but I know I do that too often for my own good 

[close]

Spoiler

Buuuut - can you explain your comment - you say it is marginally too good - then that the herd correctly decided to cube...

[close]

[stog]

Spoiler

we stole us a game

[close]

[ah_clem]

Buuuut - can you explain your comment - you say it is marginally too good - then that the herd correctly decided to cube...

It's because I was confused. I rolled out a bunch of moves yesterday and got the context mixed up.  It appears that we made a small error with this cube. 

I'm going to do a 2-ply rollout, just to be sure.

[ah_clem]

Actually, I'm confused about being confused.  The numbers posted above must have come from the planet Zaphod, because they're not anything close to what gnu  says.  No idea what happened, but here's the correct rollout:

Spoiler

Rollout details:
Centered 1-cube:
  0.787 0.133 0.008 - 0.213 0.026 0.001 CL  +0.723 CF  +0.963
[0.001 0.001 0.000 - 0.001 0.000 0.000 CL   0.002 CF   0.003]
Player Zorba owns 2-cube:
  0.805 0.133 0.019 - 0.195 0.022 0.001 CL  +1.799 CF  +1.607
[0.001 0.002 0.002 - 0.001 0.001 0.000 CL   0.010 CF   0.012]
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 903967096 and quasi-random dice
Play: 0-ply cubeful prune [expert]
Cube: 0-ply cubeful prune [expert]




1.  Double, pass         +1.000
2.  Double, take         +1.607  ( +0607)
3.  No Double            +0.963 ( -0.037)
Proper cube action: Double, pass

So, double/pass is the correct cube action (according to 0-ply rollout anyway), the Herd made the right choice, but it was a fairly close decision. Sorry about the faulty numbers, I have no idea where those numbers came from.

[close]

[Zorba]

I'd guess the first rollout was from the Herd's previous cube decision, that one was indeed too good.

[ah_clem]

I'd guess the first rollout was from the Herd's previous cube decision, that one was indeed too good.

Nope.  The rollout for the game 1 double is here:  http://www.fibsboard.com/fibsboard-forum-match-7/game-1-move-10-herd-cube-decision/

2-ply analysis and 0-ply rollout disagreed on whether it was a take, but both have holding the cube a blunder by a good margin.  We still had three checkers stuck behind a blockade, so our gammon rate was no better than our loss rate.  You usually need 2-1 ratio to play on for the gammon.  We didn't have that then.

Anyway, the erroneous numbers above aren't even close to the game 1 numbers.  I have no idea what happened.

[Zorba]

I mean the previous cube decision, in this game. The Herd's turn before this one, when I still had a checker on the bar. That position was slightly too good.

[ah_clem]

Yes, that's it exactly.  Mystery solved.  Even my comment makes sense - I just posted it to the wrong thread, perhaps due to the fact that the numbering skipped move 6 and had two move sevens.

I'll go post it in the right place.

And here I was ready to blame it all on Diane.  Oh, what the heck, I'll blame her anyway just on general principles.  (c:

[diane]

*sigh*, so much blame, so little care...