First of all, here is data for the closer decisions of 21S-43 and 51S-43 (which includes everything except a recent Snowie extension for 21S-43 of U, D and S, and recent XG 3-ply results for 51S-43 at d and s scores).
For the position you asked about, 41S-43, X is best at all scores. For money, I have this Snowie rollout:
- [X Z31 S42 D49 U60 H88] ~10*5
... and at gammon go, this GnuBG rollout:
- d[X D27 Z37 N41] /5
Key: X = hit-and-split (24/21 6/2*), Z = reverse split (24/21 13/9), S = Split (24/20 13/10), D = Down (13/10 13/9), U = Up (24/21 24/20), H = Hit (10 2*). Margins are in thousandths.
In short, the money aggs (bot aggregates) for the three positions diagrammed below are:
- 51S-43 [U D7 S9 Z12 X17]
21S-43 [X Z2 S20 D21 U26]
41S-43 [X Z31 S42 D49 U60]
The more potent and the more exposed White's builder, the more incentive Blue has to hit (anywhere). X goes from fifth place, to tied, to clearly best.
| |
|---|---|
| 51S-43 [U D7 S9 Z12 X17] | |
| |
|---|---|
| 21S-43 [X Z2 S20 D21 U26] | |
| |
|---|---|
| 41S-43 [X Z31 S42 D49 U60] | |