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Game 2 Move 17 Schigolch take?

Started by ah_clem, December 22, 2009, 03:54:37 AM

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ah_clem

we've decided to recube.  Do you take or pass?

Schigolch

Tough call, that one.
When I first looked at it, it seemed like a clear take. But I somehow hesitated - and I think I was right to hesitate. I've read your discussion, and I think it's a clear double, but I don't think anymore it's a clear take. It's rather close to a pass, given you are on roll, I have one crossing more than you and a stripped 5 point. Plus you lead the race, tho by a small margin. I reckon your winning chances are above 70%, maybe even close to the magic 75%, not far from the point I better drop.
What to do? Take, redouble, and hope to get lucky? A high double might get me into a good position, and I'll have a few opportunities to roll it. But a 44 might already be to small. Hmmm.
I think I'll throw a coin.
I won't. I'll play on, tho my chances are dim. Take. And redouble before next roll.
Thanks to the forum for the good match.

ah_clem

At this point it's just a straight race without much interesting to decide on any given move.  To save us all the tedium of voting on bear-in moves, I'm going to turn this over to blitzxz to play out the rest of the game (and match, since the cube will be at 8 in a moment) .  Hopefully he and Schigolch can arrange a time to just play it out and get back to us with the results.  This is how the previous two matches were handled and it seems to have worked pretty well.

I'll post a complete .sgf match file when it's all over.

I'm not sure who the next vict^H^H^H^H opponent is or when the next match will start. Watch this board for updates...

ah_clem

Since there are no more cube decisions to be made at this point - we're obviously going to take the cube (unless we somehow roll negative numbers and back ourselves onto the bar) and then it's just a race - I see no harm in publishing a rollout of the cube decision.

rollout

Spoiler


rkb and dorbel nailed it with their ~75% GWC estimate.  Once that number is on the table, our decision to double is just straightforward arithmetic and it's not close at all.  Our position didn't look that strong to me - I'll have to bone up on racing equities.

The take decision is interesting.  At this match score it's theoretically a take at 25%, but this is a pass at 25.5%.  I'm assuming that this is because the calculation of the take point that gives 25% involves some simplifying assumptions.  In any case, I can understand why Schigolch had to resort to a coin.




Cube analysis
Rollout cubeless equity  +0.490 (Money:  +0.490)

Cubeful equities:
1. Double, pass         +1.000
2. Double, take         +1.064  ( +0.064)
3. No double            +0.823  ( -0.177)
Proper cube action: Redouble, pass
Rollout details:
Player Forum owns 2-cube:
  0.745 0.000 0.000 - 0.255 0.000 0.000 CL  +0.490 CF  +0.823
[0.000 0.000 0.000 - 0.000 0.000 0.000 CL   0.000 CF   0.002]
Player Schigolch owns 4-cube:
  0.745 0.000 0.000 - 0.255 0.000 0.000 CL  +1.365 CF  +1.064
[0.000 0.000 0.000 - 0.000 0.000 0.000 CL   0.001 CF   0.001]
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 840571151 and quasi-random dice
Play: 0-ply cubeful prune [expert]
Cube: 0-ply cubeful prune [expert]

[close]

roadkillbooks

I think the difference comes done to what Match Equity table is used.  The follwwing are results in ExtremeGammon using different ME tables:

ExtremeGammon ME table:  REDOUBLE, TAKE:  no double +.82 (-.176), redouble take +.996, redoubledrop +1.00
It says we win 74.58% vs 25.42

Woolsey ME:REDOUBLE, TAKE: no double  +.807 (-.164), redob take +.971, redouble drop +1

Snowie ME:  REDOUBLE, DROP:  no double +.836 (-.164)
, redouble take +1.063, redouble drop +1


GNU11:  REDOUBLE, TAKE, no redouble +.826 (-.171), redouble take +.997, redouble drop +1


I find this quite interesting.  Of course ideally wed have to see how all the bots would play each others equity tables.  This is clearly as on the bubble as you can get in a non last roll situation. 

Interestingly enough.. even at 0-0 with the cube in the middle this is an initial double so the hole on the 5 point prob means more than anticipated.. prob in the sense that an early 55 is not a clincher.. i dont know.


blitzxz

And the fibsboard team won the bear off.

You tell Schigolch: you're ready?
Schigolch says: yes
Schigolch says: it ist the position last shown on fibsboard
Schigolch says: right?
Schigolch says: http://www.fibsboard.com/fibsboard-forum-match-3/game-2-move-17-schigolch-take/
You tell Schigolch: yes it is. okei i start rolling... and we got lucky 44: 11/3 9/5 4/off. 36 to you
Schigolch says: 10/4 9/6
Schigolch says: 15/21 16/19
Schigolch says: sry
You tell Schigolch: and 12: 2/off 1/off. 41 to you
You tell Schigolch: ou you roll the other? :D where are we
Schigolch says: ?
You tell Schigolch: what was that 15/21 thing?
Schigolch says: i dont know your board orinetation. what are my noumbers?
Schigolch says: do i move from big to small?
You tell Schigolch: yes the normal orientation. that 10/4 looks better. okei. so 12 bot off and 41 to you
You tell Schigolch: both
Schigolch says: 10/6 1/off
You tell Schigolch: 25:both off. 21
Schigolch says: both off
You tell Schigolch: 51: both off still. 62
Schigolch says: both off
You tell Schigolch: 65: both off. 12
Schigolch says: 3/off
You tell Schigolch: 31: 3/off 3/2 65
Schigolch says: 6/off 6/1
You tell Schigolch: 12: 4/3 2/off 35
Schigolch says: 6/1 3/off
You tell Schigolch: 65: 6/off 4/off. 64
Schigolch says: give up
Schigolch says: thx for running this
Schigolch says: congrats to the team
Schigolch says: =give up
You tell Schigolch: okei. that was nice of you to play. No luck in the end this time and team wins again. :)


stog

#6
thx schig -- hard luck ....cruel gambling cube at the end, which i think you had to take.

thx for playing - i hope you enjoyed it..

congrats Forum & cheers blitzxz for finishing for us.....