2010/09/14

The need to avoid "Double Jeopardy" is rarely exist

(Special Thanks to Karam Ashoo, who kindly corrected my english.I highlighted my mistake for a future study (of english)).
is Player 2

score: 0
pip: 91
                         
Money session
Jacoby Beaver
                          pip: 54
score: 0

is Player 1
XGID=-CCCCbB-----A---a--bbbbbb-:1:-1:1:62:0:0:3:0:10
to play 62

1.Rollout112/6 2/0ffeq: +0.921
Player:
Opponent:
95.55% (G:2.17% B:0.01%)
4.45% (G:0.00% B:0.00%)
Conf: ± 0.001 (+0.920...+0.922)
Duration: 43.6 seconds
2.Rollout112/4eq: +0.910 (-0.011)
Player:
Opponent:
95.38% (G:1.01% B:0.00%)
4.62% (G:0.02% B:0.00%)
Conf: ± 0.001 (+0.909...+0.911)
Duration: 14.6 seconds
3.XG Roller+12/6 4/2eq: +0.905 (-0.016)
Player:
Opponent:
94.90% (G:1.98% B:0.01%)
5.10% (G:0.00% B:0.00%)
4.XG Roller+12/6 3/1eq: +0.901 (-0.020)
Player:
Opponent:
94.66% (G:2.03% B:0.01%)
5.34% (G:0.00% B:0.00%)
 
1 2592 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21

I liked Kit Woolsey's article about Avoiding Double Jeopardy July-August issue 1995. Avoiding Double Jeopardy means a play that stripping the six point and leaving 6-1 and 5-1 instead of having three checkers on six point and leaving 6-5 only. ADJ is actually better is from the perspective of minimizing a shot chance in the long run.
However, Kit investigated lot lots of positions and conclude concluded that the need to avoid Double Jeopardy is very rare because of race potential and missing a chance to win Gs.

Today I revisited the positions provided by Kit and can conclude that it is even more rarer rarer than he might have thought. Position above is from Kit's article and he showed it as an example of where ADJ is right.Extreme gammon thinks the opposite. Even here ADJ is not right simply because he couldn't win as many gammons as he would with 2/off.

Even so, you should be paying attention to the score. In double match point or sort of close to it, it could easily be right to play 12/4 and ADJ, all in all, it is the safest play in terms of leaving a shot. A position below is a good example.
is Player 2

score: 0
pip: 102
                         
1 point match
                          pip: 54
score: 0

is Player 1
XGID=-CCCCcB-----A------bbbbbb-:1:-1:1:26:0:0:0:1:10
to play 26

1.Rollout112/4eq: +0.920
Player:
Opponent:
95.99% (G:26.00% B:0.00%)
4.01% (G:0.00% B:0.00%)
Conf: ± 0.001 (+0.919...+0.921)
Duration: 13.9 seconds
2.Rollout112/6 2/0ffeq: +0.913 (-0.006)
Player:
Opponent:
95.67% (G:30.81% B:0.01%)
4.33% (G:0.00% B:0.00%)
Conf: ± 0.001 (+0.912...+0.914)
Duration: 35.9 seconds
3.XG Roller12/6 4/2eq: +0.922 (+0.002)
Player:
Opponent:
96.09% (G:5.75% B:0.01%)
3.91% (G:0.00% B:0.00%)
4.XG Roller12/6 3/1eq: +0.920
Player:
Opponent:
96.01% (G:5.26% B:0.01%)
3.99% (G:0.00% B:0.00%)
 
1 1332 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

Also if two point is empty, then 6/4 would be right. It is just the safest and 4/2 won't gain as much as 2/off would.
is Player 2

score: 0
pip: 102
                         
Money session
Jacoby Beaver
                          pip: 56
score: 0

is Player 1
XGID=-D-DDcB-----A------bbbbbb-:1:-1:1:26:0:0:3:0:10
to play 26

1.Rollout112/4eq: +0.958
Player:
Opponent:
95.87% (G:4.77% B:0.00%)
4.13% (G:0.00% B:0.00%)
Conf: ± 0.001 (+0.957...+0.959)
Duration: 12.4 seconds
2.Rollout112/6 4/2eq: +0.945 (-0.013)
Player:
Opponent:
95.14% (G:5.16% B:0.00%)
4.86% (G:0.00% B:0.00%)
Conf: ± 0.001 (+0.944...+0.946)
Duration: 34.2 seconds
 
1 1508 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21

2010/09/11

Concept was right but not enough

is Player 2

score: 1
pip: 116
                         
3 point match
Crawford
                          pip: 149
score: 2

is Player 1
XGID=--aBBAB-Bb---Ca--b-cBbbAb-:0:0:1:64:2:1:1:3:10
to play 64

1.Rollout120/14* 14/10eq: -0.731
Player:
Opponent:
45.39% (G:14.75% B:0.93%)
54.61% (G:31.96% B:2.32%)
Conf: ± 0.005 (-0.736...-0.726)
Duration: 5 minutes 36 seconds
2.Rollout113/3eq: -0.784 (-0.053)
Player:
Opponent:
38.19% (G:10.60% B:0.61%)
61.81% (G:27.41% B:0.56%)
Conf: ± 0.004 (-0.788...-0.780)
Duration: 6 minutes 45 seconds
3.Rollout120/14* 5/1eq: -0.850 (-0.119)
Player:
Opponent:
40.64% (G:12.22% B:0.65%)
59.36% (G:33.15% B:1.93%)
Conf: ± 0.005 (-0.855...-0.845)
Duration: 5 minutes 21 seconds
4.Rollout220/16 20/14* eq: -0.859 (-0.127)
Player:
Opponent:
43.11% (G:13.00% B:0.85%)
56.89% (G:36.06% B:2.66%)
Conf: ± 0.005 (-0.864...-0.854)
Duration: 5 minutes 46 seconds
 
1 Truncated at 11 moves using 4 ply.
2376 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply

2 Truncated at 11 moves using 4 ply.
2375 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

My opponent hit the checker here. Even though score aruges for safe play , hitting is right. Problem with non-hitting play is that you can still lose gammon with two blots against four point board. So hitting is the right play, but he hits me wrongly. The best play is hit and run. You should remain double slotted on 23 and 20 point so that you can re-create it in case you have got return hit.

Double from the bar

is Player 2

score: 0
pip: 53
                         
3 point match
                          pip: 91
score: 0

is Player 1
XGID=-aCCBBB-A----A-------bccfA:0:0:1:00:0:0:0:3:10
on roll, cube action?


Analyzed in Rollout
No Double
  Player Winning Chances: 69.04% (G: 3.49% B: 0.11%)
  Opponent Winning Chances: 30.96% (G: 4.38% B: 0.04%)
Double/Take
  Player Winning Chances: 69.77% (G: 3.47% B: 0.10%)
  Opponent Winning Chances: 30.23% (G: 4.59% B: 0.05%)
 
Cubeless Equities
No Double:+0.369
Double:+0.975
 
Cubeful Equities
No Double:+0.584 (-0.168)
Double/Take:+0.753
Double/Drop:+1.000 (+0.247)
 
Best Cube action: Double / Take
 
Rollout details
2680 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply
 
Confidence No Double: ± 0.005 (+0.579...+0.589)
Confidence Double: ± 0.007 (+0.746...+0.759)
 
Double Decision confidence: 100.0%
Take Decision confidence: 100.0%
 
Duration: 1 minute 06 seconds

eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

Double from the bar! When take side has four point board or more, it is almost always take. Provided with bad distribution of checkers for double side, three point board can be take. Here, my opponent knows that information, but he thought it as a pass because of the score. It is a typical example of over consideration of score factor. Position first, score comes next. Position below is a good benchmarc position.
is Player 2

score: 0
pip: 53
                         
Money session
Jacoby Beaver
                          pip: 83
score: 0

is Player 1
XGID=-aBCCCC--------------bccfA:0:0:1:00:0:0:3:0:10
on roll, cube action?


Analyzed in Rollout
No Double
  Player Winning Chances: 72.81% (G: 3.69% B: 0.13%)
  Opponent Winning Chances: 27.19% (G: 0.65% B: 0.00%)
Double/Take
  Player Winning Chances: 73.51% (G: 3.69% B: 0.11%)
  Opponent Winning Chances: 26.49% (G: 0.64% B: 0.00%)
 
Cubeless Equities
No Double:+0.456
Double:+1.003
 
Cubeful Equities
No Double:+0.616 (-0.204)
Double/Take:+0.821
Double/Drop:+1.000 (+0.179)
 
Best Cube action: Double / Take
 
Rollout details
2592 Games rolled with Variance Reduction.
Dice Seed: 1341
Moves and cube decisions: 3 ply
 
Confidence No Double: ± 0.004 (+0.612...+0.621)
Confidence Double: ± 0.005 (+0.816...+0.826)
 
Double Decision confidence: 100.0%
Take Decision confidence: 100.0%
 
Duration: 37.4 seconds

eXtreme Gammon Version: 1.21

2010/09/07

is Player 2

score: 1
pip: 127
                         
5 point match
                          pip: 150
score: 2

is Player 1
XGID=-a---BDBBB-a----bbcdb-AB--:1:1:1:32:2:1:0:5:10
to play 32

1.Rollout123/21 6/3eq: -0.671
Player:
Opponent:
34.79% (G:7.19% B:0.38%)
65.21% (G:27.43% B:1.86%)
Conf: ± 0.013 (-0.684...-0.658)
Duration: 7 minutes 11 seconds
2.Rollout26/4 6/3eq: -0.702 (-0.031)
Player:
Opponent:
33.80% (G:6.14% B:0.26%)
66.20% (G:27.97% B:2.02%)
Conf: ± 0.014 (-0.716...-0.688)
Duration: 6 minutes 44 seconds
3.Rollout36/1* eq: -0.767 (-0.095)
Player:
Opponent:
26.23% (G:4.77% B:0.17%)
73.77% (G:21.08% B:1.12%)
Conf: ± 0.013 (-0.780...-0.754)
Duration: 5 minutes 15 seconds
4.Rollout39/4eq: -0.797 (-0.125)
Player:
Opponent:
29.85% (G:5.81% B:0.25%)
70.15% (G:27.47% B:1.80%)
Conf: ± 0.014 (-0.811...-0.783)
Duration: 4 minutes 06 seconds
5.Rollout37/4 6/4eq: -0.825 (-0.154)
Player:
Opponent:
27.19% (G:5.23% B:0.23%)
72.81% (G:25.47% B:1.43%)
Conf: ± 0.015 (-0.840...-0.810)
Duration: 3 minutes 57 seconds
 
1 Truncated at 11 moves using 4 ply.
410 Games rolled with Variance Reduction.
Dice Seed: 9586
Moves and cube decisions: 3 ply

2 Truncated at 11 moves using 4 ply.
409 Games rolled with Variance Reduction.
Dice Seed: 9586
Moves and cube decisions: 3 ply

3 Truncated at 11 moves using 4 ply.
289 Games rolled with Variance Reduction.
Dice Seed: 9586
Moves and cube decisions: 3 ply

eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

is Player 2

score: 2
pip: 134
                         
13 point match
                          pip: 155
score: 8

is Player 1
XGID=-a-A--E-C-a-eD-----bbAb-bA:1:1:1:62:8:2:0:13:10
to play 62

1.XG Roller+Bar/23 13/7eq: -0.643
Player:
Opponent:
33.46% (G:7.81% B:0.36%)
66.54% (G:31.72% B:2.16%)
2.XG Roller+Bar/23 8/2eq: -0.764 (-0.121)
Player:
Opponent:
30.40% (G:6.62% B:0.28%)
69.60% (G:35.66% B:2.38%)
3.XG Roller+Bar/17eq: -0.789 (-0.146)
Player:
Opponent:
29.18% (G:5.39% B:0.22%)
70.82% (G:36.27% B:1.52%)
4.2 plyBar/23 21/15eq: -0.814 (-0.171)
Player:
Opponent:
28.40% (G:5.55% B:0.22%)
71.60% (G:36.87% B:1.57%)

eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

You should stay in his inner board to establish an anchor. I was afraid of leaving too many blots, but it doesn't really matter if you have three blots or four. Highest priority here is secure your anchor.

Falafel's 52

is Player 2

score: 0
pip: 106
                         
Money session
Jacoby Beaver
                          pip: 113
score: 0

is Player 1
XGID=--Ba-BCCBA-A----abcd-bb-A-:1:-1:1:52:0:0:3:0:10
to play 52

1.XG Roller+11/9 8/3* eq: -0.380
Player:
Opponent:
43.90% (G:11.44% B:0.36%)
56.10% (G:18.56% B:1.03%)
2.XG Roller+11/9 7/2eq: -0.493 (-0.113)
Player:
Opponent:
38.42% (G:5.84% B:0.18%)
61.58% (G:11.88% B:0.40%)
3.XG Roller+8/3* 7/5eq: -0.497 (-0.117)
Player:
Opponent:
41.25% (G:10.66% B:0.34%)
58.75% (G:22.97% B:3.14%)
4.XG Roller+8/3* 5/3eq: -0.503 (-0.123)
Player:
Opponent:
41.08% (G:10.08% B:0.33%)
58.92% (G:23.12% B:2.86%)
5.XG Roller+9/4 6/4eq: -0.551 (-0.171)
Player:
Opponent:
36.70% (G:7.45% B:0.25%)
63.30% (G:10.66% B:0.45%)

eXtreme Gammon Version: 1.21

This came up in Swedish Open 2010. Several people discussed plays but only falafel got it right. It is actually clear play once you see it. You can keep him from making 5point by putting him on the bar. Making 4point is really bad play because it gave opponent too many good numbers.