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obvious is not always right
01-23-2015
, 07:31 AM
Code:
1. 13/11 6/5 Eq.: -0,172
0,456 0,096 0,004 - 0,544 0,185 0,004 CL -0,177 CF -0,172
2. 7/5 6/5 Eq.: -0,321 ( -0,149)
0,414 0,097 0,004 - 0,586 0,149 0,004 CL -0,223 CF -0,321
3. 6/5 6/4 Eq.: -0,326 (-0,154)
0,437 0,091 0,004 - 0,563 0,287 0,006 CL -0,324 CF -0,326
Truncated cubeful rollout (depth 10) with var.redn.
147 games, Mersenne Twister dice gen. with seed 769866802 and quasi-random dice
Stop when std.errs. are small enough: ratio 0,1 (min. 144 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Code:
1. 13/11 6/5 Eq.: -0,363
0,414 0,064 0,002 - 0,586 0,237 0,003 CL -0,346 CF -0,363
2. 13/11 7/6 Eq.: -0,466 ( -0,103)
0,366 0,058 0,002 - 0,634 0,130 0,002 CL -0,340 CF -0,466
01-23-2015
, 07:32 PM
01-24-2015
, 07:14 AM
01-24-2015
, 09:40 PM
01-25-2015
, 07:21 AM
01-25-2015
, 01:06 PM
As Taper_Mike already suggested, white is likely to leave a blot next turn, and even when he has got all his checkers in his board, blue probably is not out of hitting chances. Is it worth to give up the 3-point backgame with a board that looks deplorable? Covering the checker on the 1-point spoils the opportunity to get another checker, so he would like to recycle it. However, with a missing 5 and 6 point blue has no strong case, and on top of that you give white an opportunity to make his 3-point. Creating a 4-point board is much more important.
Also if he would not be able to cover, he should not hit:
Truncated cubeful rollout (depth 10) with var.redn.
145 games, Mersenne Twister dice gen. with seed 769929098 and quasi-random dice
Stop when std.errs. are small enough: ratio 0,1 (min. 144 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
In the thread when to hit in a 3-point backgame I will show in which cases hitting is right.
Code:
1. 9/8 7/1 Eq.: -0,357
0,396 0,032 0,001 - 0,604 0,305 0,016 CL -0,496 CF -0,357
2. 21/15 7/6 Eq.: -0,395 ( -0,038)
0,412 0,029 0,001 - 0,588 0,367 0,027 CL -0,540 CF -0,395
3. 22/16*/15 Eq.: -0,520 ( -0,162)
0,363 0,044 0,001 - 0,637 0,385 0,034 CL -0,647 CF -0,520
Also if he would not be able to cover, he should not hit:
Code:
1. 21/14 Eq.: -0,423
0,407 0,026 0,001 - 0,593 0,379 0,027 CL -0,565 CF -0,423
2. 22/16* 10/9 Eq.: -0,456 ( -0,033)
0,374 0,050 0,001 - 0,626 0,359 0,023 CL -0,584 CF -0,456
145 games, Mersenne Twister dice gen. with seed 769929098 and quasi-random dice
Stop when std.errs. are small enough: ratio 0,1 (min. 144 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
In the thread when to hit in a 3-point backgame I will show in which cases hitting is right.
Last edited by yogiman; 01-25-2015 at 01:15 PM.
01-25-2015
, 10:48 PM
Black to Play 6-5
XGID=--BBBBCA-A----b-ccbd-Ba---:0:0:1:65:0:0:0:0:10
White - Pips 114
Black - Pips 104
The usual: what would you play, and why?
Mike
XGID=--BBBBCA-A----b-ccbd-Ba---:0:0:1:65:0:0:0:0:10
White - Pips 114
Black - Pips 104
The usual: what would you play, and why?
Mike
01-27-2015
, 07:45 PM
Black to Play 6-5
XGID=--BBBBCA-A----b-ccbd-Ba---:0:0:1:65:0:0:0:0:10
White - Pips 114
Black - Pips 104
To a beginner, it may be obvious to make the ace point. To a more experienced player, it may be clear that Black must race, and take this opportunity to run a checker to the safety of his outer board. But neither of these is right. The top three plays all have Black breaking anchor with the 6, but then stopping on the 15pt, where White will have a direct shot at him! How can this be?
Two factors are at work. The first is White’s blot on his 3pt. With a nasty five-point board looming on the other side, White will not be in a mood to hit unless he can cover up at the same time. “So what?” you might say. “White will still hit when it is advantageous to him. Why give him the free shots?”
The answer may found by looking at the second factor, which is White’s rolls of 61, 63, and 64. When the 15pt is empty, White will use those to make his 5pt. When, however, a Black checker is stationed on the 15pt, White will be forced to play safe, moving one or two of his valuable spares behind Black’s straggler. Among non-doublets, White has only 6 other rolls that make his 5pt. Killing White’s 6s cuts the number of non-doublets that make the 5pt in half.
Like the posters who replied to this problem, my OTB play was 21/10. At first, I was mystified by 21/15 9/4, but then I noticed the 6s. Running all the way is only a small error, sacrificing about 22 millipoints of equity.
5k XG2 Rollout – Unlimited Game , No Jacoby, No Beavers
Mike
XGID=--BBBBCA-A----b-ccbd-Ba---:0:0:1:65:0:0:0:0:10
White - Pips 114
Black - Pips 104
To a beginner, it may be obvious to make the ace point. To a more experienced player, it may be clear that Black must race, and take this opportunity to run a checker to the safety of his outer board. But neither of these is right. The top three plays all have Black breaking anchor with the 6, but then stopping on the 15pt, where White will have a direct shot at him! How can this be?
Two factors are at work. The first is White’s blot on his 3pt. With a nasty five-point board looming on the other side, White will not be in a mood to hit unless he can cover up at the same time. “So what?” you might say. “White will still hit when it is advantageous to him. Why give him the free shots?”
The answer may found by looking at the second factor, which is White’s rolls of 61, 63, and 64. When the 15pt is empty, White will use those to make his 5pt. When, however, a Black checker is stationed on the 15pt, White will be forced to play safe, moving one or two of his valuable spares behind Black’s straggler. Among non-doublets, White has only 6 other rolls that make his 5pt. Killing White’s 6s cuts the number of non-doublets that make the 5pt in half.
Like the posters who replied to this problem, my OTB play was 21/10. At first, I was mystified by 21/15 9/4, but then I noticed the 6s. Running all the way is only a small error, sacrificing about 22 millipoints of equity.
5k XG2 Rollout – Unlimited Game , No Jacoby, No Beavers
Code:
XGID=--BBBBCA-A----b-ccbd-Ba---:0:0:1:65:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
Pip count X: 104 O: 114 X-O: 0-0
Cube: 1
X to play 65
1. Rollout¹ 21/15 9/4 eq:-0.158
Player: 45.49% (G:10.40% B:0.12%)
Opponent: 54.51% (G:4.49% B:0.13%)
Confidence: ±0.0069 (-0.1651..-0.1514) - [96.6%]
2. Rollout¹ 21/15 6/1 eq:-0.167 (-0.009)
Player: 45.25% (G:10.92% B:0.14%)
Opponent: 54.75% (G:6.12% B:0.32%)
Confidence: ±0.0062 (-0.1732..-0.1608) - [3.2%]
3. Rollout¹ 21/15 7/2 eq:-0.172 (-0.013)
Player: 45.04% (G:9.82% B:0.11%)
Opponent: 54.96% (G:4.65% B:0.14%)
Confidence: ±0.0068 (-0.1784..-0.1649) - [0.2%]
4. Rollout¹ 21/10 eq:-0.181 (-0.022)
Player: 44.63% (G:8.59% B:0.11%)
Opponent: 55.37% (G:2.79% B:0.08%)
Confidence: ±0.0067 (-0.1872..-0.1739) - [0.0%]
¹ 2592 Games rolled with Variance Reduction.
Dice Seed: 32175630
Moves: 3-ply, cube decisions: XG Roller
eXtreme Gammon Version: 2.10
Last edited by Taper_Mike; 01-27-2015 at 08:02 PM.
01-28-2015
, 06:36 AM
Position ID: /LwTACBsWxAANw Match ID: UokWAAAACAAE