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Cube action - RO

Posted By: Daniel Murphy
Date: Sunday, 30 December 2012, at 3:13 p.m.

In Response To: Cube action - RO (Rick Janowski)

Rick: XGR++ analysis indicates that only the 14 & 16 point gives a marginal double/pass (I had expected the 14 & 15 point combination to be slightly worse in reality, so this was surprising to me).

I think I can explain that in part.

First, having blots on the 14 and 15 points does not (according to Gnubg 2-ply) give Blue 2/36 more hitting numbers. In both positions, Blue should hit with 18/36 numbers. Blue should refrain from hitting with 2/36 numbers with blots on 14 and 16, and with 4/36 numbers with blots on 14 and 15: With blots on 14 and 16, Blue should play 53 16/11 14/11. If White remains blotted on the bar point, Blue's only bad numbers are 52 and 62 (and 52 can be played safely). With blots on 14 and 15, Blue should play 21 15/13 14/13 and 43 15/11 14/11. If White remains blotted on the bar point, again only 62 forces Blue to leave a direct shot. White will often run, after which Blue will leave an indirect shot at most, and sometimes make the bar point, after which only 62 forces a shot.

But having blots on the 14 and 15 points gives White slightly more return hits, 129/1296 instead of 112/1296. The extra 17/1296 shots all come after Blue's nonhitting, nonclearing numbers, further weakening Blue's relatively weaker rolls.

Blue's Roll	Blots on 14 and 16	Blots on 14 and 15
Hitting number	60/1296 hitting returns	60/1296 hitting returns
Nonhitting number	52/1296 hitting returns	69/1296 hitting returns

Roll	Blots on 14 and 16		Blots on 14 and 15
	Hit?	Returns	Hit?	Returns
65	No	16	No	0
21	Yes	12	No	0
43	Yes	12	No	0
54	Yes	12	No	0
11	Yes	0	Yes	0
31	Yes	0	Yes	0
32	Yes	0	Yes	0
33	Yes	0	Yes	0
63	Yes	0	Yes	0
52	Yes	12	Yes	12
61	Yes	12	Yes	12
55	No	0	No	0
51	No	16	No	16
22	No	4	Yes	6
62	No	8	Yes	12
44	No	0	Yes	6
66	No	0	No	7
41	No	8	No	16
53	No	0	Yes	12
42	No	0	No	14
64	No	0	No	16
Total	18/36	112/1296	18/36	129/1296

Messages In This Thread

• Cube action?
  Mr Majestyk -- Friday, 28 December 2012, at 11:04 p.m.
  • Cube action?
    John O'Hagan -- Friday, 28 December 2012, at 11:52 p.m.
  • Cube action - RO
    Mr Majestyk -- Saturday, 29 December 2012, at 11:52 p.m.
    • Cube action - RO
      Casper van der Tak -- Saturday, 29 December 2012, at 11:57 p.m.
      • Variants
        Mr Majestyk -- Sunday, 30 December 2012, at 1:37 a.m.
        • Variants
          Casper van der Tak -- Sunday, 30 December 2012, at 8:30 a.m.
    • Cube action - RO
      Rick Janowski -- Sunday, 30 December 2012, at 10:08 a.m.
      • Cube action - RO
        Daniel Murphy -- Sunday, 30 December 2012, at 3:13 p.m.