Backgammon Brain Busters #70

by Michael Strato
28 March 2006

Strategy Talk

Players of all levels are invited to share their view on these interesting positions that we came across while honing our backgammon skills in match play.

Is the computer program always right? As we have seen in the past, even the best programs get certain scenarios wrong while world class human players have a better grasp of these situations through the experience of years of play.

The "Brain Busters" series offers three new backgammon positions in each article, problems that we believe to be challenging and worthy of thought and discussion - please post your opinion on how you would play these positions in the forum thread below.

We will do their rollouts with Snowie 4 Pro and publish the results along with a new set of positions about once a week. Enjoy!

Note: See the rollouts results of all previous Brain Busters articles at this link.

Please give us your thoughts on these without the help of a bot.

Position 1:


		Pip: 194
		9 point match Green-White: Score 2-0
		Pip: 104

Position 2:


		Pip: 196
		5 point match Green-White: Score 0-0
		Pip: 172

Position 3:


		Pip: 99
		5 point match Green-White: Score 0-0
		Pip: 30

WARNING! - ROLLOUTS

April 3, 2006: This is the final article in the Brain Busters series.

Here are the Snowie rollouts for the three positions above:

Position 1:


		Pip: 194
		9 point match Green-White: Score 2-0
		Pip: 104

#		Ply	Move	Equity
	1	R	18/2*	1.683
			8.0% 75.1% 88.2% 11.8% 1.2% 0.0%
			95% confidence interval: - money cubeless eq.: 1.581 ±0.036. Rollout settings: Full rollout, 144 games (equiv. 3267 games), played 3-ply (precise), random seed, with race database.
	2	R	18/10 7/3 6/2*	1.674 (-0.009)
			9.5% 76.5% 87.7% 12.3% 2.6% 0.2%
			95% confidence interval: - money cubeless eq.: 1.586 ±0.043. Rollout settings: Full rollout, 144 games (equiv. 2856 games), played 3-ply (precise), random seed, with race database.
	3	R	18/14 13/9 7/3 6/2*	1.674 (-0.010)
			8.9% 75.7% 87.2% 12.8% 1.0% 0.1%
			95% confidence interval: - money cubeless eq.: 1.578 ±0.038. Rollout settings: Full rollout, 144 games (equiv. 2482 games), played 3-ply (precise), random seed, with race database.
	4	R	18/10 13/9 6/2*	1.655 (-0.028)
			8.9% 73.7% 87.4% 12.6% 1.7% 0.1%
			95% confidence interval: - money cubeless eq.: 1.556 ±0.038. Rollout settings: Full rollout, 144 games (equiv. 3052 games), played 3-ply (precise), random seed, with race database.
	5	R	18/14 6/2*(3)	1.623 (-0.061)
			7.3% 74.9% 86.0% 14.0% 1.7% 0.2%
			95% confidence interval: - money cubeless eq.: 1.522 ±0.045. Rollout settings: Full rollout, 144 games (equiv. 3571 games), played 3-ply (precise), random seed, with race database.

Position 2:


		Pip: 196
		5 point match Green-White: Score 0-0
		Pip: 172

#		Ply	Move	Equity
	1	R	23/18* 10/9	0.906
			7.1% 43.2% 72.3% 27.7% 4.2% 0.3%
			95% confidence interval: - money cubeless eq.: 0.903 ±0.057. Rollout settings: Full rollout, 144 games (equiv. 1623 games), played 3-ply (precise), random seed, with race database.
	2	R	23/18*/17	0.876 (-0.029)
			6.5% 43.7% 71.3% 28.7% 4.4% 0.3%
			95% confidence interval: - money cubeless eq.: 0.880 ±0.058. Rollout settings: Full rollout, 144 games (equiv. 2094 games), played 3-ply (precise), random seed, with race database.
	3	R	9/3*	0.858 (-0.048)
			8.4% 41.6% 70.5% 29.5% 5.3% 0.2%
			95% confidence interval: - money cubeless eq.: 0.855 ±0.049. Rollout settings: Full rollout, 144 games (equiv. 2442 games), played 3-ply (precise), random seed, with race database.
	4	R	23/18* 9/8	0.838 (-0.068)
			6.4% 41.3% 70.6% 29.4% 4.3% 0.1%
			95% confidence interval: - money cubeless eq.: 0.846 ±0.060. Rollout settings: Full rollout, 144 games (equiv. 1707 games), played 3-ply (precise), random seed, with race database.
	5	R	23/18* 22/21	0.825 (-0.080)
			7.1% 42.3% 70.2% 29.8% 5.1% 0.3%
			95% confidence interval: - money cubeless eq.: 0.844 ±0.050. Rollout settings: Full rollout, 144 games (equiv. 3321 games), played 3-ply (precise), random seed, with race database.
	6	R	24/18*	0.780 (-0.126)
			7.3% 38.8% 69.2% 30.8% 4.5% 0.3%
			95% confidence interval: - money cubeless eq.: 0.798 ±0.056. Rollout settings: Full rollout, 144 games (equiv. 1813 games), played 3-ply (precise), random seed, with race database.

Position 3:


		Pip: 99
		5 point match Green-White: Score 0-0
		Pip: 30

#		Ply	Move	Equity
	1	R	17/9	1.313
			0.2% 38.0% 91.7% 8.3% 0.0% 0.0%
			95% confidence interval: - money cubeless eq.: 1.217 ±0.009. Rollout settings: Full rollout, 576 games (equiv. 21972 games), played 3-ply (precise), random seed, with race database.
	2	R	17/11 3/1	1.230 (-0.083)
			0.2% 33.5% 90.8% 9.2% 0.0% 0.0%
			95% confidence interval: - money cubeless eq.: 1.153 ±0.009. Rollout settings: Full rollout, 576 games (equiv. 21060 games), played 3-ply (precise), random seed, with race database.