Yes, 2-ply's evaluation of game winning chances might be a clue that that 2-ply is clueless. I suspect a Gnubg 2-ply rollout will get close to zero wins for Blue. A human can do better.
In this position Gnubg's 0-ply, 1-ply, 2-ply, 3-ply and 4-ply analyses are worthless. Blue does not win 36% 0- and 2-ply) or 31% (4-ply). And neither 16/12 3/1, 23/19 17/15, 23/19 3/1, 17/13 16/14 nor 23/19 16/14 is Blue's best play.
There's no reason to break the 3 point now -- although all four of Blue's homeboard checkers would be better placed 18 pips back, it would be better to break the 2 point instead of the 3 point, and Blue should make two prime making plays in a row (this turn, and next turn hopefully hitting and continuing with prime-making) instead of using half this roll on 3-1 and possibly giving White a tempo move after a hit next roll. There's also no reason to break the 23 point now. Blue gets more shots with the 23 point intact. And there's no reason to make the 13 point now. There is a reason to put the second and now useless spare on the 24 point to work prime-building with its companions on the 19-16 points.
One could roll out something like this ...
The score (after 0 games) is: White 0, Blue 0 (match to 1 point, post-Crawford play)
Move number 5: Blue to play 23
| White | 10 |
|---|---|
| |
| Blue | 229 |
Position ID: LAAAYAMQtbADAA Match ID: cAktAAAAAAAA | |
... just to see how a bot does with it -- note that Gnubg 2-ply thinks 2-2 wins 55% from here -- but in that rollout 2-ply would be making dumb plays like this ...
The score (after 0 games) is: White 0, Blue 0 (match to 1 point, post-Crawford play)
Move number 60: White to play 16
| White | 66 |
|---|---|
| |
| Blue | 162 |
Position ID: NhtQEioAADACAA Match ID: MIE4AAAAAAAA | |
• White moves 21/14
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| • | 1 | 2 | 21/14 | +0.0808 |
| 0.5404 0.0522 0.0228 - 0.4596 0.0000 0.0000 | ||||
| 2 | 2 | 24/17 | +0.0537 ( -0.0271) | |
| 0.5268 0.0706 0.0296 - 0.4732 0.0000 0.0000 | ||||
and this ...
The score (after 0 games) is: White 0, Blue 0 (match to 1 point, post-Crawford play)
Move number 23: Blue to play 44
| White | 58 |
|---|---|
| |
| Blue | 232 |
Position ID: AEAQwQBW2qQCAA Match ID: cAkyAAAAAAAA | |
• Blue moves 18/10*(2)
Alert: very bad move ( -0.153)
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| 1 | 2 | 22/18 20/12 16/12 | +0.6981 | |
| 0.8490 0.0000 0.0000 - 0.1510 0.0549 0.0360 | ||||
| • | 9 | 2 | 18/10*(2) | +0.5455 ( -0.1525) |
| 0.7728 0.0000 0.0000 - 0.2272 0.0587 0.0397 | ||||
3-ply checker play should better than 2-ply, for both sides (1-ply would probably better, too).