Opening Rolls

Forum Archive : Opening Rolls

Opening 51: Rollout

From:   Stick
Date:   26 February 2006
Subject:   Opening 5-1 Easy but questions
Forum:   GammOnLine

All the opening moves have already been rolled out this extensively
cubeless. To access these rollouts just visit You can infer what to play
at certain match scores from the cubeless rollouts, but if I was going
to infer I'd at least prefer the cubeful rollouts. Here, with an opening
5-1 for example, you will not see much difference between the cubeful
and cubeless rollouts. I'd expect to see a bigger difference on an
opening 2-1 cubeful vs. cubeless though.

If we are to generalize for match play from this rollout, it would mean
that a 5-1 should be split at every possible score since it wins the
most games by splitting, wins the most gammons, and loses the least
amount of gammons. This may not be the case and a rollout 'according to
score' would need to verify this information, which I one day may do but
that's very far down the road, as I prefer money play.

Does anyone here still slot or slot at certain match scores? If so, why?
I might consider slotting against a weaker player, hoping to lead the
game into a more complicated setting, but in general I make the split.

As always, feel free to visit my site,, where I
will be updating things on a daily basis but don't expect to be done for
quite some time still.

1. 24/23 13/8
    P(W) P(WG) P(WBG)   P(L) P(LG) P(LBG)  Cubeless  Cubeful
   .5011 .1381 .0061 - .4989 .1342 .0053   +0.0069   +0.0057  (Equity)
   .0003 .0003 .0001   .0003 .0003 .0001    0.0007    0.0024  (StdErr)

2. 13/8 6/5
    P(W) P(WG) P(WBG)   P(L) P(LG) P(LBG)  Cubeless  Cubeful
   .4979 .1374 .0058 - .5021 .1373 .0074   -0.0058   -0.0041  (Equity)
   .0003 .0003 .0001   .0003 .0003 .0001    0.0008    0.0021  (StdErr)

Full cubeful rollout with var. redn.  46656 games, Mersenne Twister dice
gen. with seed 988950592 and quasi-random dice.
Play: 2-ply cubeful prune [world class] keep the first 0 0-ply moves and
up to 12 more moves within equity 0.16. Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
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Opening Rolls

At different match scores  (Louis Nardy Pillards, July 2002) 
Average advantage of winning opening roll  (Chuck Bower, Oct 1998) 
Choosing a strategy  (Daniel Murphy, June 2001) 
Early game rule of thumb  (Rich Munitz, Feb 2009) 
Factors to consider  (Kit Woolsey, July 1994) 
How computers play  (Kit Woolsey, Mar 1995)  [Recommended reading]
Magriel's Chapter 5  (Hayden Alfano+, May 2006)  [Long message]
Mloner vs Jellyfish  (Kit Woolsey, Dec 1995) 
Nactating a whole game  (Nack Ballard+, Jan 2011)  [Long message]
Nactation  (Jim Stutz+, June 2010) 
Nactation overview  (Nack Ballard, Oct 2009) 
Nactation--Why use it?  (leobueno+, Jan 2011) 
Opening 1's: Split or slot?  (Douglas Zare, Dec 2003) 
Opening 21: Rollout  (Stick, Mar 2006)  [GammOnLine forum]
Opening 21: Split or slot?  (Dick Adams+, Dec 2003) 
Opening 32: Rollout  (Stick, Feb 2006)  [GammOnLine forum]
Opening 43: In GOL online match  (Raccoon+, Feb 2004)  [GammOnLine forum]
Opening 43: Pros and cons  (Stick+, Jan 2006)  [GammOnLine forum]
Opening 43: Which split is better?  (Peter Backgren+, Aug 2000) 
Opening 43: Which split is better?  (Michael J. Zehr+, Mar 1996) 
Opening 51: Rollout  (Stick, Feb 2006)  [GammOnLine forum]
Opening 52: Merits of splitting  (Peter Bell, Apr 1995) 
Opening 53: Magriel's recommendation  (George Parker+, July 1997)  [Long message]
Opening 53: Split to 21?  (Alex Zamanian, Aug 2000) 
Opening 53: Why make the three point?  (Kit Woolsey+, Feb 1996) 
Opening 6's: Slot the bar point?  (Chuck Bower+, Feb 2000) 
Opening 6's: Slot the bar point?  (David Montgomery, June 1995) 
Opening 62: Could running be best?  (Gary Wong, Sept 1997) 
Opening 62: Split, run, or slot?  (Chuck Bower, May 1997) 
Opening 63: Middle Eastern split?  (Mark+, Apr 2002) 
Opening 63: Slot the four point?  (Dennis Cartwright+, Mar 2002) 
Opening 64: Make the two point?  (William Hill+, Jan 1998) 
Opening 64: Make the two point?  (Darse Billings, Feb 1995) 
Opening 64: Rollout  (Peter Grotrian, Jan 2006)  [GammOnLine forum]
Opening 64: Split to 20?  (Peter Bell, June 1995) 
Opening 64: Three choices  (Brian Sheppard, July 1997) 
Opening 65: Becker on lover's leap  (Jeffrey Spiegler+, Aug 1991) 
Opening 65: Computer rankings  (Chuck Bower, Jan 1997) 
Opening rolls ranked  (Arthur+, Apr 2005) 
Rollouts of opening 21 and replies  (Alexander Nitschke, Oct 1997) 
Rollouts of openings  (Tom Keith+, Jan 2006) 
Rollouts: Expert Backgammon  (Tom Fahland, Aug 1994) 
Rollouts: Jellyfish 3.0  (Midas+, Sept 1997) 
Rollouts: Jellyfish 3.0 level 6  (Chuck Bower, Feb 1999)  [Recommended reading]
Rollouts: Snowie 4.1  (Rene Cerutti, Apr 2004) 
Slotting the four point  (Joe Loria+, Oct 1999) 
Snowie's openers and replies  (rcerutti, Feb 1999)  [Long message]
Splitting versus building  (Dave Slayton+, Aug 2000) 
Splitting versus slotting  (Daniel Murphy, Apr 2001) 
Splitting versus slotting  (Daniel Murphy, Sept 1997) 
Trice's rankings  (Marty Storer, Feb 1992) 

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