Strategy · Opening rolls

Opening roll 6-4: three very different plays, all good

You won the opening roll-off with a 6 and a 4. In GNU Backgammon’s rollouts the best play is 24/14. The rollouts cannot separate it from 8/2 6/2: the gap, 0.016, is inside their margin of error.

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Board 1 · The best play, 24/14, in amber.

Why 24/14

Three plays with nothing in common score almost the same. 24/14 runs one back checker most of the way out, 8/2 6/2 makes your 2-point, and 24/18 13/9 splits and brings a builder down.

The top five plays, rolled out

#PlayEquityBehind the bestWinsGammons won · lost3-ply (rank)
124/14+0.009 ±0.013—50.4%12.9% · 13.7%+0.012 (#3)
28/2 6/2−0.007 ±0.0160.016 ≈49.5%16.5% · 14.8%+0.015 (#1)
324/18 13/9−0.012 ±0.0140.021 ≈50.1%14.5% · 14.6%+0.012 (#2)
424/20 24/18−0.051 ±0.0140.06049.1%11.8% · 15.2%−0.062 (#5)
524/20 13/7−0.057 ±0.0140.06648.4%13.9% · 14.7%−0.052 (#4)

Equity is the average result in points per game for the player on roll, with the cube in play: each play rolled out 1,296 times, ± one standard error. Gammons include backgammons. ≈ marks a play behind the best by less than twice the larger standard error, inside the margin of error.

The alternatives

The rollouts put the three within 0.021 of each other, inside their margin of error, so pick the plan you play best. 24/20 13/7 and splitting both back checkers with 24/20 24/18 are clearly worse.

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Board 2 · The runner-up, 8/2 6/2, in teal.
All 14 legal plays, ranked at 3-ply
  1. 8/2 6/2 +0.015
  2. 24/18 13/9 +0.012
  3. 24/14 +0.012
  4. 24/20 13/7 −0.052
  5. 24/20 24/18 −0.062
  6. 13/9 13/7 −0.064
  7. 13/3 −0.089
  8. 24/18 6/2 −0.128
  9. 24/18 8/4 −0.146
  10. 24/20 8/2 −0.161
  11. 13/7 6/2 −0.167
  12. 13/7 8/4 −0.167
  13. 13/9 8/2 −0.171
  14. 8/4 8/2 −0.368

Questions about the 6-4 opening

What is the best opening move for 6-4 in backgammon?

24/14 and 8/2 6/2 are effectively tied. In GNU Backgammon rollouts of the top five plays, 24/14 scores +0.009 and 8/2 6/2 −0.007, a gap inside the margin of error.

Is 8/2 6/2 a mistake with an opening 6-4?

No. It finishes 0.016 behind 24/14 in GNU Backgammon’s rollouts, inside their margin of error, so the two plays are effectively equal.

How was this 6-4 analysis made?

GNU Backgammon 1.07.001 ranked all 14 legal plays at 3-ply, then rolled out the best five, 1,296 games each, with the cube in play (money game, Jacoby off). GNU Backgammon 1.06.002, the version Boardgammon’s servers run, ranks the same five plays in the same order at 3-ply.

How these numbers were made

GNU Backgammon 1.07.001 ranked every legal play at 3-ply with the cube in play (money game, Jacoby off, no beavers), then rolled out the best five: 1,296 games each, with variance reduction and quasi-random dice. GNU Backgammon 1.06.002, the version Boardgammon’s servers run, ranks the same five plays in the same order at 3-ply. Evaluated on 2026-10-20. The same engine analyses every finished online game on Boardgammon: see how that compares. New to the numbers? Read what equity and a rollout are.


Terms on this page: Running game, Point, Builder, Blot. Next in the strategy guides: cube theory.