I am with Stick and Bob on this. I can't reproduce this. I tried it two ways. I took your position and pasted it into Gnubg and then used hint to produce a 4ply analysis. I then pasted your position in and then had GnuBG "end the game" so there was a match to analyse. The results are below. On 4 ply the output looks correct. A thing to note is that the output in your post for the 4 ply of 9/6 9/5 appears to actually be the 0 ply values! I believe there is a bug somewhere but like Stick I think its how you are using GnuBG that is cauing the issues. If you could send me an email with the Build number and exact instruction (exactly what you do to produce these odd results). The more detailed the better. Can you email me your SGF file. Its clear from your output that this position was part of a match (since the move the player made is highlighted). Lastly, did you happen to do a Rollout on this position and/or use Cmark prior to looking at the 4 ply analysis?
The score (after 0 games) is: gnubg 3, mpetch 0
Move number 6: gnubg to play 34
| gnubg | 91 |
|---|---|
| |
| mpetch | 104 |
Position ID: 1a4pwABsd7YAAA Match ID: EYERADAAAAAA | |
• gnubg moves 10/6 4/1
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| 1 | 4 | 10/6 5/2 | +0.558 | |
| 0.810 0.002 0.000 - 0.190 0.000 0.000 | ||||
| 4-ply cubeful prune | ||||
| 2 | 4 | 10/3 | +0.555 ( -0.003) | |
| 0.809 0.002 0.000 - 0.191 0.000 0.000 | ||||
| 4-ply cubeful prune | ||||
| • | 3 | 4 | 10/6 4/1 | +0.551 ( -0.007) |
| 0.807 0.002 0.000 - 0.193 0.000 0.000 | ||||
| 4-ply cubeful prune | ||||
| 4 | 4 | 9/6 9/5 | +0.542 ( -0.017) | |
| 0.801 0.009 0.000 - 0.199 0.002 0.000 | ||||
| 4-ply cubeful prune | ||||
| 5 | 2 | 10/6 9/6 | +0.537 ( -0.021) | |
| 0.799 0.009 0.001 - 0.201 0.003 0.000 | ||||
| 2-ply cubeful prune [world class] | ||||
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| • | 1 | 0 | 10/6 4/1 | +0.551 |
| 0.807 0.005 0.000 - 0.193 0.001 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 2 | 0 | 10/6 5/2 | +0.548 ( -0.003) | |
| 0.806 0.004 0.000 - 0.194 0.001 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 3 | 0 | 10/3 | +0.529 ( -0.022) | |
| 0.797 0.004 0.000 - 0.203 0.001 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 4 | 0 | 6/2 5/2 | +0.383 ( -0.168) | |
| 0.732 0.015 0.000 - 0.268 0.005 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 5 | 0 | 10/6 9/6 | +0.376 ( -0.175) | |
| 0.728 0.015 0.000 - 0.272 0.003 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 6 | 0 | 6/3 5/1 | +0.356 ( -0.195) | |
| 0.721 0.016 0.000 - 0.279 0.008 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 7 | 0 | 10/6 8/5 | +0.353 ( -0.198) | |
| 0.719 0.016 0.000 - 0.281 0.005 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||
| 8 | 0 | 9/6 9/5 | +0.350 ( -0.201) | |
| 0.716 0.020 0.000 - 0.284 0.006 0.000 | ||||
| 0-ply cubeful prune [expert] | ||||