BGonline.org Forums

Rollouts: This seems to be a very subtle position!

Posted By: Timothy Chow
Date: Sunday, 25 April 2010, at 11:53 p.m.

In Response To: 4-away/5-away checker play (Timothy Chow)

I haven't rolled out the cube decisions yet; it's possible that I missed a double here though I think it's close. I am more interested in the checker play because it seems quite baffling. Below are the rollouts ATS, for money, and at GS and GG. To summarize, the standout play for money/GS/DMP is 24/18*/13. (I didn't roll out DMP but since the cubeless wins are so much higher for 24/18*/13 than for any other play in all four rollouts I'm pretty sure it's the DMP play; plus intuitively one expects the escaping play to be best at DMP.) At GG, the plays 24/18* 6/1* and 10/4 6/1* and 13/8 10/4 are all reasonable choices, but 24/18*/13 is clearly worse.

OTB, I thought that at a 4-away score I should be looking for a gammonish blitzing play, despite being ahead in the match. I played 10/4 6/1*. As mentioned above, this would be a fine play at GG, but it's apparently a blunder at 4-away/5-away as well as for money. O.K., fine; perhaps that just means that 4-away/5-away is a "normal" score and I should have played the "normal" move 24/18*/13? While the rollout suggests that that would have been all right, it also likes 13/8 10/4 ATS but not at any of the other scores, except GG. So I really don't know what to make of these rollout results. Perhaps I should repeat the money and 4-away/5-away rollouts with the cube turned.

gnubg	148
tchow	147
Position ID: 4OvIAyBoZ+IDIA Match ID: cAn3ACAAGAAA

---

At 4-away/5-away:

#		Ply	Move	Equity
•	1	R	13/8 10/4	+0.675
			0.633 0.200 0.008 - 0.367 0.078 0.004 +0.445 +0.675 0.001 0.002 0.001 - 0.001 0.001 0.000 0.003 0.008
	2	R	24/18*/13	+0.670 ( -0.005)
			0.660 0.160 0.008 - 0.340 0.072 0.003 +0.447 +0.670 0.001 0.001 0.001 - 0.001 0.001 0.000 0.003 0.007
	3	R	24/18* 13/8	+0.651 ( -0.023)
			0.639 0.198 0.018 - 0.361 0.093 0.005 +0.431 +0.651 0.001 0.002 0.001 - 0.001 0.001 0.000 0.004 0.010
			Full cubeful rollout with var.redn.
			2592 games, Mersenne Twister dice gen. with seed 855142532 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	4	R	24/18* 6/1*	+0.590 ( -0.085)
			0.613 0.228 0.016 - 0.387 0.108 0.006 +0.400 +0.590 0.002 0.002 0.001 - 0.002 0.002 0.001 0.005 0.013
	5	R	24/18* 10/5	+0.565 ( -0.110)
			0.620 0.194 0.017 - 0.380 0.097 0.004 +0.383 +0.565 0.001 0.002 0.002 - 0.001 0.001 0.000 0.004 0.011
	6	R	10/4 6/1*	+0.551 ( -0.125)
			0.603 0.236 0.013 - 0.397 0.090 0.005 +0.416 +0.551 0.001 0.002 0.001 - 0.001 0.001 0.001 0.004 0.010
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 854074762 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

---

For money with Jacoby (probably should have done this without Jacoby, but hopefully it doesn't make all that much difference):

#		Ply	Move	Equity
•	1	R	24/18*/13	+0.310
			0.672 0.153 0.007 - 0.328 0.066 0.003 +0.435 +0.310 0.002 0.002 0.001 - 0.002 0.001 0.000 0.004 0.006
	2	R	24/18* 13/8	+0.261 ( -0.049)
			0.643 0.194 0.010 - 0.357 0.089 0.004 +0.397 +0.261 0.002 0.002 0.001 - 0.002 0.001 0.000 0.004 0.009
	3	R	13/8 10/4	+0.248 ( -0.062)
			0.638 0.185 0.005 - 0.362 0.073 0.003 +0.391 +0.248 0.002 0.002 0.001 - 0.002 0.001 0.000 0.004 0.006
	4	R	24/18* 6/1*	+0.208 ( -0.102)
			0.617 0.222 0.010 - 0.383 0.100 0.006 +0.362 +0.208 0.002 0.002 0.001 - 0.002 0.002 0.001 0.006 0.009
	5	R	24/18* 10/5	+0.207 ( -0.103)
			0.629 0.183 0.010 - 0.371 0.090 0.004 +0.357 +0.207 0.002 0.002 0.001 - 0.002 0.001 0.000 0.004 0.007
	6	R	10/4 6/1*	+0.202 ( -0.108)
			0.611 0.225 0.007 - 0.389 0.086 0.003 +0.365 +0.202 0.002 0.002 0.001 - 0.002 0.001 0.000 0.004 0.006
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 854441897 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

---

At gammon save:

#		Ply	Move	Equity
•	1	R	24/18*/13	+0.186
			0.662 0.284 0.026 - 0.338 0.069 0.004 +0.186 +0.186 0.002 0.007 0.003 - 0.002 0.001 0.001 0.005 0.005
	2	R	13/8 10/4	+0.123 ( -0.064)
			0.638 0.264 0.020 - 0.362 0.077 0.004 +0.123 +0.123 0.002 0.007 0.002 - 0.002 0.001 0.001 0.004 0.004
	3	R	24/18* 13/8	+0.078 ( -0.108)
			0.628 0.298 0.049 - 0.372 0.088 0.007 +0.078 +0.078 0.002 0.007 0.004 - 0.002 0.002 0.001 0.006 0.006
	4	R	24/18* 10/5	+0.038 ( -0.148)
			0.618 0.309 0.046 - 0.382 0.099 0.006 +0.038 +0.038 0.002 0.007 0.003 - 0.002 0.002 0.001 0.006 0.006
	5	R	10/4 6/1*	+0.029 ( -0.158)
			0.605 0.299 0.025 - 0.395 0.091 0.005 +0.029 +0.029 0.002 0.006 0.003 - 0.002 0.002 0.001 0.005 0.005
	6	R	24/18* 6/1*	+0.009 ( -0.177)
			0.606 0.307 0.027 - 0.394 0.102 0.009 +0.009 +0.009 0.003 0.007 0.002 - 0.003 0.002 0.001 0.007 0.007
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 853810937 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

---

At gammon go:

#		Ply	Move	Equity
•	1	R	24/18* 6/1*	+0.681
			0.626 0.214 0.018 - 0.374 0.145 0.016 +0.681 +0.681 0.002 0.002 0.002 - 0.002 0.005 0.002 0.006 0.006
	2	R	10/4 6/1*	+0.680 ( -0.000)
			0.602 0.238 0.014 - 0.398 0.131 0.013 +0.680 +0.680 0.002 0.002 0.002 - 0.002 0.005 0.002 0.006 0.006
	3	R	13/8 10/4	+0.670 ( -0.011)
			0.618 0.217 0.006 - 0.382 0.123 0.010 +0.670 +0.670 0.002 0.002 0.001 - 0.002 0.005 0.002 0.005 0.005
	4	R	24/18* 13/8	+0.655 ( -0.025)
			0.649 0.179 0.020 - 0.351 0.128 0.012 +0.655 +0.655 0.002 0.002 0.002 - 0.002 0.004 0.002 0.006 0.006
	5	R	24/18*/13	+0.647 ( -0.033)
			0.669 0.155 0.011 - 0.331 0.114 0.007 +0.647 +0.647 0.002 0.002 0.001 - 0.002 0.005 0.001 0.005 0.005
	6	R	24/18* 10/5	+0.638 ( -0.043)
			0.636 0.183 0.020 - 0.364 0.133 0.013 +0.638 +0.638 0.002 0.002 0.002 - 0.002 0.005 0.002 0.006 0.006
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 854557226 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

Messages In This Thread

• 4-away/5-away checker play
  Timothy Chow -- Saturday, 24 April 2010, at 8:47 p.m.
  • 4-away/5-away checker play
    Martin -- Sunday, 25 April 2010, at 8:43 a.m.
    • 4-away/5-away checker play
      Leonardo Jerkovic -- Sunday, 25 April 2010, at 2:07 p.m.
  • 4-away/5-away checker play
    Casper van der Tak -- Sunday, 25 April 2010, at 2:19 p.m.
    • 4-away/5-away checker play
      Daniel Murphy -- Sunday, 25 April 2010, at 8:43 p.m.
      • Money with or without Jacoby?
        Casper van der Tak -- Sunday, 25 April 2010, at 9:06 p.m.
        • Money with or without Jacoby?
          Timothy Chow -- Monday, 26 April 2010, at 3:33 p.m.
  • 4-away/5-away checker play
    Timothy Chow -- Sunday, 25 April 2010, at 5:29 p.m.
  • Rollouts: This seems to be a very subtle position!
    Timothy Chow -- Sunday, 25 April 2010, at 11:53 p.m.
    • Rollouts: This seems to be a very subtle position!
      Martin -- Monday, 26 April 2010, at 5:37 a.m.
      • Rollouts: This seems to be a very subtle position!
        Timothy Chow -- Wednesday, 28 April 2010, at 3:31 a.m.