Intro 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18

 
BACKGAMMON BY THE BAY
Problem #31 solution
  		Match to 11
Blue 10 (Crawford), White 7

0123456bar789101112

0123456bar789101112
     Blue to play 64

Candidate plays:

  1. 13/7 13/9
  2. 7/1 7/3

[PREV][NEXT]

                   

RK:
Blue has a good racing lead and just wants to get home safely. Should he volunteer a direct shot now, or hope to never have to leave a shot?

If Blue plays 13/7 13/9 and White misses (with 23 numbers), Blue is in great shape, with a nice racing lead and only minimal danger of leaving future shots. And if Blue gets hit, all is not lost either, because he has good chances to enter from the bar and possibly hit White.

Now suppose Blue plays safe, making the 5-point board. Now he must hope for doubles to clear the midpoint; or that he'll only have to leave an indirect shot when White is forced to clear the midpoint. However, with most non-6s, White can keep both the midpoint and 5-point anchor, while making a 5-point board. Now any 6 except 66 for Blue, plus 54 and 44, leaves a direct shot, at a time when it's more dangerous to get hit.

All in all, it looks like paying now is the winner, given the ease of winning if White misses, plus the remaining chances if White hits.

One thing to notice: the rollouts show about a 6% edge for 13/7 13/9. However, Blue wins slightly more gammons than after 7/1 7/3. Those probably happen when White hits but Blue hits back from the bar, leaving White with 4 blots. At this match score, those gammons are worth zero to Blue, which means that playing safe isn't quite as bad at this score. But based on the wins alone, it's still correct to leave the shot now. 

Pip counts:          Blue    81                     White  110

                     Blue                           White              
Candidate Plays      Equity   Win    G/BG    BG     Win    G/BG    BG  
13/7 13/9            +0.523   73.2%   7.9%   0.2%   26.8%   2.2%   0.1%
7/1 7/3              +0.464   71.4%   5.8%   0.2%   28.6%   2.5%   0.0%




HOME
 
TOURNEYS
 
RESULTS
 
BROWNIE-POINTS
 
RATINGS
 
MEMBERS
 
ANNOTATED-GAMES
 
SONGS
 
CONTACTS

Copyright © 1996-2005 BackGammon By the Bay
Online Backgammon | Gammon Empire | Backgammon FAQ | RedTop's Backgammon Pages | Webby's Backgammon Site | Gratis Backgammon