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How to estimate chances of hitting shot?

Posted By: Mr Majestyk
Date: Monday, 26 November 2012, at 8:37 p.m.

In Response To: How to estimate chances of hitting shot? (AP)

I've altered the position to show the winning chances in a pure race. All popular racing formulae will be in this 4% ballpark.

 White is Player 1 score: 0 pip: 95 Unlimited Game pip: 67 score: 0 Blue is Player 2
XGID=--BBBBCA----A--B-b-d-ccc--:1:-1:-1:00:0:0:0:0:10
Blue on roll, cube action?
 Analyzed in XG Roller++ No redouble Redouble/Take Player Winning Chances: 96.32% (G:0.04% B:0.00%) 96.37% (G:0.05% B:0.00%) Opponent Winning Chances: 3.68% (G:0.00% B:0.00%) 3.63% (G:0.00% B:0.00%) Cubeless Equities +0.927 +1.856 Cubeful Equities No redouble: +1.000 Redouble/Take: +1.833 (+0.832) Redouble/Pass: +1.000 (0.000) Best Cube action: Too good to redouble / Pass Percentage of wrong take needed to make the double decision right: 0.0%

eXtreme Gammon Version: 2.03

In the position posted, you'll get a shot 8 in 36 rolls or 22% of the time. You'll hit on average 36% of the time or 8% i.e. 22 x 36%. Its a little higher than 1/3 here since blue could roll 64 giving you a maximum of 15 shots in 36 or roll 63 giving you a minimum of 11 shots in 36. Its less than 8% as Blue could roll any of his 7 in 36 good rolls which translates to 8 - (8 x 19.4%) = 6.5%. Blue maybe able to play safely for 3 rolls giving you 3 attempts to hit a shot at 6.5% per shot or 19.5%. Your overall chances are 19.5 + 4 = 23.5%.

 White is Player 1 score: 0 pip: 101 Unlimited Game pip: 73 score: 0 Blue is Player 2
XGID=--BBBBCA----A-b---Bd-ccc--:1:-1:-1:00:0:0:0:0:10
Blue on roll, cube action?

eXtreme Gammon Version: 2.03

NBM

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