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What would you have done OTB RESULTS and OTB thinking

Posted By: Bob Koca
Date: Monday, 25 June 2012, at 5:12 p.m.

In Response To: What would you have done OTB (Joe Russell)

Joe was the only person who came close to getting it right. Thinking though that it might sometimes be right to play on with 2 on the 8 point is not enough. If the oppponent's roll makes it right to play on with two on the 8 it may be right by only a little meaning it may have been better to play inside with a little less gammon chances at no risk. Also if opponent rolls well except for 66 it is a small gammon chance for you but being able to correctly play on after playing inside is worth something.

This is a good example of where Kleinmann count ideas come in handy. Blue has pipcount of 53 after the play and supposing that played one form the 8 point I estimated the wastage by comparing to the 13.7 wasteage from closed board with spares on 1,2,3 which I have as a refernce position. The position would be a little worse than that and I estimated wastage of 15. The opponent needs 40 pips to run off the gammon and I estimated wastage as 7. These EPCS are like a normal long race with pipcount of 39 to 60. The lower variability in number of turns to bearoff helps the race leader (which is opponent racing to be off the gammon) and I think that a one pip adjustment is about right for that. So using Kleinmann with 38 to 60 gives D = 26, S = 94, D^2/S = 7 which maps to a little less than 3%. So I figured it would indeed usually only be a play on with two on the 8 by a very small amount and figured from there that the risk was not worth it.

A couple scenarios are worth noting.

If you knew opponent was going to roll 21 then equity after 6/1 5/1 is 1.016 and equity after 8/4 6/1 is 1.022 with no double. If the gammon chance is greater than the more efficient race play is worthwhile.

However the borderline cash comes already after 41 for opponent when 8/4 6/1 is 1.002 after ND. After a 41 there is equity of 1.015 after playing inside.

Messages In This Thread

• What would you have done OTB
  Bob Koca -- Tuesday, 19 June 2012, at 3:50 p.m.
  • What would you have done OTB
    Daniel Murphy -- Tuesday, 19 June 2012, at 4:50 p.m.
  • What would you have done OTB
    Chuck Bower -- Tuesday, 19 June 2012, at 4:57 p.m.
  • What would you have done OTB
    Timothy Chow -- Tuesday, 19 June 2012, at 5:34 p.m.
  • What would you have done OTB
    David Rennie -- Tuesday, 19 June 2012, at 6:55 p.m.
    • What would you have done OTB
      Prince Barlow -- Tuesday, 19 June 2012, at 7:41 p.m.
  • What would you have done OTB
    ah_clem -- Tuesday, 19 June 2012, at 9:30 p.m.
  • What would you have done OTB
    Joe Russell -- Wednesday, 20 June 2012, at 12:36 a.m.
    • What would you have done OTB RESULTS and OTB thinking
      Bob Koca -- Monday, 25 June 2012, at 5:12 p.m.