Running with the two back checkers is best. It wasn't my first play (making the 20 and 2), nor XG++ (20, 9, and 10/6) but after you look at it and think about it, the logic is there: Blue has a race lead and if he isn't hit in the outfield next he is a favorite to make an inside pt such that the cube is becoming a relevant factor in the following rolls. This running play is relevant for more opening 43D-xx-44 sequences with similar characteristics such as 43D-64R-44.
I noticed a dilemma in the replies of which 5 to choose. I will share my view as to why making the home-board 5 pt isn't a relevant option in this case. It reminds me of the the two sequences from the 31 Opening Book (I have only praising words on this book): 43S-42P-31, and 54S-42P-31. For the first sequence, making the 20 pt is correct and for the latter making the 5 pt is correct. The reason is that for the first sequence you have more diversified numbers to make the 5 (or possibly 4) pt next so you need to make the harder pt to get first and for the latter both the 5 and 20 pts are (almost) equally hard to make so you prefer the 5 pt. This principle is relevant here and in many more opening positions. After 43D you have so many numbers that make the 5 pt that if you get a chance, you should make the 20 pt first and hope not to get hit and make the 5 pt next. Neither was the top play for the opening sequence at hand but I find this principle to be useful in many opening cases in which I need to choose which 5 to make.
Thanks to David Rockwell for sharing this rollout.
        
 
          
 | | White is Player 2
score: 0
pip: 156 | Unlimited Game
Jacoby Beaver | pip: 160
score: 0
Blue is Player 1 |
|
| XGID=-a----E-CAA-fC---c-e----B-:0:0:1:44:0:0:3:0:10 |
| Blue to play 44 |
| 1. | Rollout1 | 24/16(2) | eq: +0.372 |
| Player:
Opponent: | 59.70% (G:10.87% B:0.24%)
40.30% (G:6.36% B:0.22%) | Conf.: ± 0.006 (+0.366...+0.379) - [100.0%]
Duration: 1 hour 35 minutes |
|
| 2. | Rollout1 | 24/20(2) 13/9 10/6 | eq: +0.349 (-0.023) |
| Player:
Opponent: | 57.95% (G:14.45% B:0.30%)
42.05% (G:5.49% B:0.22%) | Conf.: ± 0.007 (+0.343...+0.356) - [0.0%]
Duration: 1 hour 15 minutes |
|
| 3. | Rollout1 | 24/20(2) 6/2(2) | eq: +0.343 (-0.030) |
| Player:
Opponent: | 57.08% (G:15.92% B:0.38%)
42.92% (G:5.71% B:0.25%) | Conf.: ± 0.007 (+0.336...+0.350) - [0.0%]
Duration: 1 hour 19 minutes |
|
| 4. | Rollout1 | 24/20(2) 8/4(2) | eq: +0.329 (-0.043) |
| Player:
Opponent: | 56.52% (G:17.02% B:0.33%)
43.48% (G:5.67% B:0.24%) | Conf.: ± 0.007 (+0.322...+0.336) - [0.0%]
Duration: 1 hour 13 minutes |
|
| 5. | XG Roller++ | 24/20 13/5 9/5 | eq: +0.291 (-0.082) |
| Player:
Opponent: | 55.56% (G:17.99% B:0.58%)
44.44% (G:8.97% B:0.37%) | |
|
| |
1 5184 Games rolled with Variance Reduction.
Dice Seed: 45638915
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.10