Thanks, David, for posting such an interesting position. Kudos to Tim and Mick for sussing out 7/2. The reasons they gave are plausible, suggesting, at the least, that earning a triple shot by playing 7/2 needs to be on all lists of candidate plays.
Mike
  White is Player 2
score: 5 pip: 64  7 point match  pip: 105 score: 4
Blue is Player 1  
XGID=BABBBAbBCabccd:0:0:1:51:4:5:0:7:10 
Blue to play 51 
1.  Rollout^{1}  13/8 7/6  eq: 0.148 
 Player: Opponent:  39.63% (G:3.38% B:0.12%) 60.37% (G:1.94% B:0.01%)  Conf.: ± 0.001 (0.149...0.147)  [93.6%] Duration: 1 hour 17 minutes 

2.  Rollout^{1}  13/12 7/2  eq: 0.149 (0.001) 
 Player: Opponent:  41.56% (G:5.71% B:0.24%) 58.44% (G:8.44% B:0.05%)  Conf.: ± 0.001 (0.150...0.148)  [6.4%] Duration: 1 hour 18 minutes 

3.  Rollout^{2}  13/8 4/3  eq: 0.167 (0.019) 
 Player: Opponent:  39.36% (G:3.38% B:0.13%) 60.64% (G:2.37% B:0.01%)  Conf.: ± 0.002 (0.169...0.165)  [0.0%] Duration: 19 minutes 11 seconds 

4.  Rollout^{2}  13/12 11/6  eq: 0.167 (0.020) 
 Player: Opponent:  41.40% (G:9.18% B:0.55%) 58.60% (G:14.61% B:0.18%)  Conf.: ± 0.002 (0.170...0.165)  [0.0%] Duration: 21 minutes 16 seconds 

5.  Rollout^{2}  13/7  eq: 0.172 (0.024) 
 Player: Opponent:  38.81% (G:3.53% B:0.12%) 61.19% (G:2.25% B:0.01%)  Conf.: ± 0.002 (0.174...0.170)  [0.0%] Duration: 19 minutes 56 seconds 


^{1} 62208 Games rolled with Variance Reduction. Dice Seed: 91329371 Moves: 3ply, cube decisions: XG Roller
^{2} 15552 Games rolled with Variance Reduction. Dice Seed: 91329371 Moves: 3ply, cube decisions: XG Roller

Rollout by Taper_Mike 2015Feb19 eXtreme Gammon Version: 2.10.199.2658 Flashcard PositionID 000954.32.xgp 
eXtreme Gammon Version: 2.10, MET: Kazaross XG2