13/8 seems to be a more viable candidate than I expected.

              
 
              
 | | White is Player 2
score: 0 pip: 108 | | 1 point match | pip: 154 score: 0
Blue is Player 1 | |
| XGID=------EbBC--bC-----cdBb-b-:0:0:1:32:0:0:0:1:10 |
| Blue to play 32 |
| 1. | XG Roller+ | 6/4 6/3 | eq: -0.158 |
| Player: Opponent: | 42.12% (G:8.11% B:0.30%) 57.88% (G:18.76% B:0.47%) | |
|
| 2. | XG Roller+ | 13/8 | eq: -0.187 (-0.029) |
| Player: Opponent: | 40.66% (G:7.39% B:0.25%) 59.34% (G:17.49% B:0.42%) | |
|
| 3. | XG Roller+ | 9/4 | eq: -0.198 (-0.041) |
| Player: Opponent: | 40.09% (G:7.50% B:0.27%) 59.91% (G:19.69% B:0.64%) | |
|
| 4. | XG Roller+ | 13/10 6/4 | eq: -0.210 (-0.053) |
| Player: Opponent: | 39.48% (G:7.35% B:0.29%) 60.52% (G:23.04% B:0.58%) | |
|
| 5. | XG Roller+ | 8/5 6/4 | eq: -0.242 (-0.084) |
| Player: Opponent: | 37.90% (G:6.66% B:0.25%) 62.10% (G:24.46% B:0.70%) | |
|
eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross

              
 
              
 | | White is Player 2
score: 0 pip: 118 | | 1 point match | pip: 90 score: 0
Blue is Player 1 | |
| XGID=-Bab-BEBBB-------a-bcbb-b-:0:0:1:21:0:0:0:1:10 |
| Blue to play 21 |
| 1. | XG Roller+ | 9/8 9/7 | eq: +0.608 |
| Player: Opponent: | 80.42% (G:11.47% B:0.22%) 19.58% (G:0.76% B:0.01%) | |
|
| 2. | XG Roller+ | 6/5 6/4 | eq: +0.502 (-0.107) |
| Player: Opponent: | 75.08% (G:15.00% B:0.43%) 24.92% (G:3.86% B:0.06%) | |
|
eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross
Variant:

              
 
              
 | | White is Player 2
score: 0 pip: 110 | | 1 point match | pip: 90 score: 0
Blue is Player 1 | |
| XGID=-Bab-BEBBB---------bbbcab-:0:0:1:21:0:0:0:1:10 |
| Blue to play 21 |
| 1. | XG Roller+ | 9/8 9/7 | eq: +0.636 |
| Player: Opponent: | 81.78% (G:9.06% B:0.14%) 18.22% (G:0.43% B:0.01%) | |
|
| 2. | XG Roller+ | 6/5 6/4 | eq: +0.623 (-0.013) |
| Player: Opponent: | 81.16% (G:18.80% B:0.67%) 18.84% (G:1.85% B:0.03%) | |
|
eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross
Original position at gammon go:

              
 
              
 | | White is Player 2
score: 2 pip: 118 | | 4 point match | pip: 90 score: 0
Blue is Player 1 | |
| XGID=-Bab-BEBBB-------a-bcbb-b-:1:-1:1:21:0:2:0:4:10 |
| Blue to play 21 |
| 1. | XG Roller+ | 6/5 6/4 | eq: +0.799 |
| Player: Opponent: | 74.46% (G:15.49% B:0.48%) 25.54% (G:4.10% B:0.07%) | |
|
| 2. | XG Roller+ | 9/8 9/7 | eq: +0.793 (-0.006) |
| Player: Opponent: | 80.66% (G:8.98% B:0.18%) 19.34% (G:0.94% B:0.02%) | |
|
eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross
Only 21% wins apparently.

              
 
              
 | | White is Player 2
score: 4 pip: 133 | | 7 point match | pip: 77 score: 5
Blue is Player 1 | |
| XGID=-BABbDC-bB-A-----aacbbb---:0:0:1:00:5:4:0:7:10 |
| Blue on roll, cube action? |
| Analyzed in XG Roller+ |
| Player Winning Chances: | 78.77% (G: 12.13% B: 0.15%) |
| Opponent Winning Chances: | 21.23% (G: 1.66% B: 0.07%) |
| |
| Cubeless Equities |
| No Double: | +0.790 |
| Double: | +1.762 |
| |
| Cubeful Equities |
| No Double: | +0.937 (-0.063) |
| Double/Take: | +1.253 (+0.253) |
| Double/Drop: | +1.000 |
| |
| Best Cube action: Double / Drop |
| |
eXtreme Gammon Version: 1.21, MET: Rockwell-Kazaross