Question:
4-3?
Option 1: 13/9 13/10
votes: 0
Option 2: 13/6
votes: 0
Option 3: 13/9 7/4
votes: 5
Option 4: 13/10 7/3
votes: 4
Option 5: 7/3 6/3
votes: 0
Spoiler
I don't want to leave a direct shot. If he hits it, he'll probably cover his slotted 3 point and we're on the bar againsta four point board. So we have to move the checker on the 7. Following it up with moving the spare from the six is safe for now, but it seems passive and leads to an inflexible position. Indirect shots are not so bad because he can't hit and cover - we'll get good counterplay with him having 5(!) blots hanging around after hitting in our outfield.
So safety the blot on the 7 and bring down a builder from the midpoint. There are two ways to do it, and I think 7/4 is slightly more flexible than 7/3, but I doubt there's much difference between the two. So, 13/9 7/4.
Spoiler
I first voted for the passive play but changed my mind after reading ah_clem's good analysis, so thanks for that. I think maybe 13/9, 7/4 also shades it over 13-/0, 7/3, because, if we get hit, at least we haven't then duped our 3s to both come on and make a return hit on our 10-point. All ifs, buts and maybes but I guess that's what this game is all about. So 13/9, 7/4.
Spoiler
So it comes down to 13/9 7/4 or 13/10 7/3. Do we put the indirect shot 7 points away or 8 points away? Usually this is an easy decision - there are six ways to roll a seven or an eight, so the risk is the same either way, but being eight away gives you more return shots if your opponent tries to run. So the usual thing to do is move to 8 away.
But in this case, he's not going to be running (unless he can hit) and fours are blocked so eight away has one fewer hitting roll. It really comes down to whether it's worth taking the extra risk of one extra shot vs. the increased flexibility of a spare on the 4 pt vs a spare on the 3. I'm thinking ahead to the bear-in, so I'm favoring the more flexible play, but perhaps this is premature and immediate safety is more important.
All this being said, I doubt the two moves differ by more than the margin of error.
rollout
Spoiler
For what it's worth.... the Herd's play is marginally better than the runner up. I didn't bother to roll out the other plays - 2-ply analysis has them as triple whoppers.
1. Rollout 13/9 7/4 Eq.: +0.161
0.657 0.133 0.017 - 0.343 0.062 0.003 CL +0.298 CF +0.161
[0.002 0.003 0.002 - 0.002 0.001 0.001 CL 0.005 CF 0.006]
2. Rollout 13/10 7/3 Eq.: +0.148 ( -0.013)
0.658 0.112 0.012 - 0.342 0.061 0.002 CL +0.296 CF +0.148
[0.002 0.002 0.002 - 0.002 0.001 0.000 CL 0.005 CF 0.006]
Full cubeful rollout with var.redn.
1296 games, Mersenne Twister dice gen. with seed 903967096 and quasi-random dice
Play: 0-ply cubeful [expert]
Cube: 0-ply cubeful [expert]
3. Cubeful 2-ply 13/6 Eq.: -0.117 ( -0.278)
0.589 0.139 0.011 - 0.411 0.107 0.003
2-ply cubeful prune [world class]
4. Cubeful 2-ply 13/10 13/9 Eq.: -0.120 ( -0.281)
0.588 0.216 0.027 - 0.412 0.162 0.011
2-ply cubeful prune [world class]
5. Cubeful 2-ply 7/3 6/3 Eq.: -0.237 ( -0.397)
0.566 0.078 0.001 - 0.434 0.094 0.002
2-ply cubeful prune [world class]