Cleveland

I was busy at Cleveland Open last weekend.  Only one match was recorded there, the semifinals versus Dmitriy.  Unfortunately for me I played terible and deserved to lose, which I did.  I may look at some of those blunders later. 

Today I would like to share a few key positions that were recorded and/or from memory.

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First, I am on roll leading 5 away 6 away and holding a 2 cube. Cube action?

is Ed score: 3 pip: 29

9 point match

pip: 27 score: 4 is Bill

XGID=---ABBA------------bbaa---:1:1:1:00:4:3:0:9:10

on roll, cube action?

Analyzed in Rollout	No redouble	Redouble/Take
Player Winning Chances:	72.31% (G:0.00% B:0.00%)	72.29% (G:0.00% B:0.00%)
Opponent Winning Chances:	27.69% (G:0.00% B:0.00%)	27.71% (G:0.00% B:0.00%)
Cubeless Equities	+0.446	+1.009
Cubeful Equities
No redouble:	+0.702 (-0.111)	±0.000 (+0.702..+0.703)
Redouble/Take:	+0.814	±0.001 (+0.813..+0.814)
Redouble/Pass:	+1.000 (+0.186)
Best Cube action: Redouble / Take
Rollout details
20736 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:		100.0%
Take Decision confidence:		100.0%
Duration: 14.3 seconds

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

I redoubled and Ed took.

My thought process.  Use EPC.  I have 27 pips + 6 for wastage or 33 EPC.
33/7 is 4 - 3 is 1.  Therefore Ed's point of last take for money is 34.

I did not make any adjustment for match score - I just assumed his 4 cube takepoint was similar to money.

Ed has 29 pips + 6 for wastage or 35 EPC.  Therefore the position is Redouble / Pass.

So by my calculation at the table the position was Redouble / Pass.  This is obviously wrong.  That said, I am not sure where I ade my mistake(s).   Comments welcome.

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Later in the same game.  Ed trails 5 away 6 away and is on roll.  Cube action?

is Ed score: 3 pip: 11

9 point match

pip: 9 score: 4 is Bill

XGID=----AA--------------aa-a--:2:-1:-1:00:4:3:0:9:10

on roll, cube action?

Analyzed in XG Roller++	No redouble	Redouble/Take
Player Winning Chances:	63.29% (G:0.00% B:0.00%)	63.29% (G:0.00% B:0.00%)
Opponent Winning Chances:	36.71% (G:0.00% B:0.00%)	36.71% (G:0.00% B:0.00%)
Cubeless Equities	+0.266	+0.649
Cubeful Equities
No redouble:	+0.389 (-0.260)
Redouble/Take:	+0.649
Redouble/Pass:	+1.000 (+0.351)
Best Cube action: Redouble / Take

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

Ed redoubled to 8 and I took.

My thought process.  I can drop or play for the match.  If I drop my match equity is 2 away 5 away or about 25%.  So I need >25% winning chances to take, else I should drop.

My rough winning chances are (Ed misses) x (I win).  I can also win a few odd times when Ed fails to bear off in two rolls, but let's ignore those.
Ed wins immediately with double 4 ro better, or he fails to win immediately with 33 rolls.

I then win on my turn with 10 numbers (any combo of 654 plus double 3's). 

So out of a crosssection of 1296 games, I win 32 x 10 or 320.  This is about 25% by itself so once you add-on the extra wins I have a take. 

++++

Still, I feel like I must be doing something wrong here.  The computer says my win chances are in fact close to 37%,  much higher than 25%.  What gives? 

Perhaps there are actually many many more variations where Ed fails to bear off in two rolls than I appreciated at the time. 
Well any ace kinda sucks for Ed and 32 and 43 aren't the best either.  So about 15 rolls and Ed is hardly a lock to get off next time.  Let's say he gets off 70% of the time on the second roll after he misses..

So I get 15/36 * 30% or ~12.5% extra wins...
except that ~30% of the time when he misses I win anyway so I really only capture 70% of that 12.5% or just under 9%.

Adding 9% to my baseline of 25% gets me to 34%, fairly close to the 36.7% XG gives me.  Still confused as to the math on this, but at least I am closer.

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The next position is approximate from memory.  I trail 6 away 8 away and Prince is on roll.  Cube action?

is Prince score: 3 pip: 79

9 point match

pip: 113 score: 1 is Bill

XGID=---aBBCDC--------aabbbbbbA:1:-1:-1:00:1:3:0:9:10

on roll, cube action?

Analyzed in XG Roller++	No redouble	Redouble/Take
Player Winning Chances:	75.27% (G:25.18% B:0.04%)	75.94% (G:23.24% B:0.03%)
Opponent Winning Chances:	24.73% (G:1.58% B:0.03%)	24.06% (G:1.63% B:0.03%)
Cubeless Equities	+0.753	+1.228
Cubeful Equities
No redouble:	+0.783
Redouble/Take:	+0.771 (-0.012)
Redouble/Pass:	+1.000 (+0.217)
Best Cube action: No redouble / Take
Percentage of wrong pass needed to make the double decision right: 5.1%

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

Prince redoubled and I took. 

My thinking at the table.  This is mostly a score based take as for money I think this is a drop.  Prince has overage on his gammons since a gammon win takes him to 11 points.  I don't know my takepoint but assume it is close to money, perhaps a bit lower due to being behind.

The main thing I was looking at was the possibility of recubing to 8.  I can perfetly use all 8 points to win the match right here and now.  So I figured it is a take, as long as I recube aggressively if given the chance.

*************

Memo.  Same position for money.  Prince holds 2 cube and is on roll.  Cube action?

is Prince score: 0 pip: 79

Unlimited Game Jacoby Beaver

pip: 113 score: 0 is Bill

XGID=---aBBCDC--------aabbbbbbA:1:-1:-1:00:0:0:3:0:10

on roll, cube action?

Analyzed in XG Roller++	No redouble	Redouble/Take
Player Winning Chances:	75.38% (G:25.25% B:0.04%)	75.61% (G:24.92% B:0.04%)
Opponent Winning Chances:	24.62% (G:1.56% B:0.03%)	24.39% (G:1.63% B:0.04%)
Cubeless Equities	+0.744	+1.490
Cubeful Equities
No redouble:	+0.943 (-0.057)
Redouble/Take:	+1.325 (+0.325)
Redouble/Pass:	+1.000
Best Cube action: Redouble / Pass

eXtreme Gammon Version: 2.02

Redouble and big pass for money as the above shows.

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Later in the same game.  I trail 6 away 8 away and am on roll holding a 4 cube.  Cube action?

is Prince score: 3 pip: 69

9 point match

pip: 113 score: 1 is Bill

XGID=---aBBCDC-----------dccbbA:2:1:1:00:1:3:0:9:10

on roll, cube action?

Analyzed in XG Roller++	No redouble	Redouble/Take
Player Winning Chances:	46.07% (G:2.31% B:0.06%)	46.20% (G:2.67% B:0.09%)
Opponent Winning Chances:	53.93% (G:10.57% B:0.03%)	53.80% (G:9.81% B:0.02%)
Cubeless Equities	-0.098	+0.302
Cubeful Equities
No redouble:	+0.222 (-0.080)
Redouble/Take:	+0.302
Redouble/Pass:	+1.000 (+0.698)
Best Cube action: Redouble / Take

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

I rolled.

I knew in my gut this was a redouble and was in fact part of the reason I took on 4 in the first place.  But when it came to crunch time I wimped out.

This is one of those weird score based cubes where you can redouble as an underdog.

**********

This is the first game of a 9 point match.  (Position approximate from memory)  I hold a 2 cube and am on roll.  Cube action?

is Mary score: 0 pip: 158

9 point match

pip: 82 score: 0 is Bill

XGID=cCBBCC----------bbccbB----:1:1:1:00:0:0:0:9:10

on roll, cube action?

Analyzed in Rollout	No redouble	Redouble/Take
Player Winning Chances:	58.07% (G:44.73% B:0.50%)	57.64% (G:44.81% B:0.50%)
Opponent Winning Chances:	41.93% (G:8.38% B:0.32%)	42.36% (G:7.14% B:0.32%)
Cubeless Equities	+0.555	+1.077
Cubeful Equities
No redouble:	+0.610	±0.012 (+0.598..+0.622)
Redouble/Take:	+0.593 (-0.017)	±0.016 (+0.577..+0.609)
Redouble/Pass:	+1.000 (+0.390)
Best Cube action: No redouble / Take
Percentage of wrong pass needed to make the double decision right: 4.0%
Rollout details
1296 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller
Double Decision confidence:		95.5%
Take Decision confidence:		100.0%
Duration: 8 minutes 17 seconds

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

My prior roll was a superjoker from hell.  I rolled double 3 which hit two checkers, closed a 5 point board, and advanced my back guy from the 24 point to the 21 point. 

To be honest I had no idea what is going on here so I just doubled.  Mary dropped.  Hard to blame her really - my wins are mostly gammons, vaulting me to 8-0 Crawford.  Pretty scary indeed yet apparently her position is so strong that it isn't even a recube.

**********

Finally I have a 63 to play at DMP.

is Carol score: 0 pip: 128

2 point match

pip: 133 score: 0 is Bill

XGID=aa-C-BCAB----Ab--bBbcbb-A-:1:1:1:63:0:0:0:2:10

to play 63

1.	Rollout1	24/18 13/10	eq: +0.143
	Player: Opponent: 57.15% (G:15.39% B:0.99%) 42.85% (G:17.10% B:1.18%) Conf.: ± 0.006 (+0.137...+0.149) - [100.0%] Duration: 1 minute 24 seconds
2.	Rollout2	13/7 8/5	eq: +0.104 (-0.039)
	Player: Opponent: 55.19% (G:19.31% B:1.28%) 44.81% (G:16.32% B:1.46%) Conf.: ± 0.007 (+0.097...+0.111) - [0.0%] Duration: 1 minute 18 seconds
3.	Rollout3	18/15 13/7	eq: +0.089 (-0.054)
	Player: Opponent: 54.46% (G:16.54% B:1.47%) 45.54% (G:18.52% B:3.06%) Conf.: ± 0.007 (+0.082...+0.096) - [0.0%] Duration: 1 minute 18 seconds
1 611 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller 2 612 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller 3 613 Games rolled with Variance Reduction. Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.02, MET: Kazaross XG2

I went for broke with 18/15, 13/7.  I figured I had to make the bar to contain her back checkers and then 18/15 was the most logical 3.  Gammons don't matter so put'em where you want em.  This sort of puts the game on the line.

A better BIG PLAY was simply escaping the back checker with 24/18, 13/10.  This puts tremendous pressure on Carol to roll well from the bar else the game is almost over.  With my play, I still have to clean up some blots and escape my back man.  With the computer's play I simply have to come home safe if missed  - easier.