I think I complete the 5 prime. As always my reasoning is a little sketchy, but white will be facing a cube that is tough to take without a good roll on the next throw. My cube play is horrendous though, so perhaps basing my checker play on a dubious cube decision the next throw is not the right way to approach these problems.
Consecutive 5-primes are much stronger than broken ones. Consider what happens when Black hits a shot somewhere down the road. If Black has five in a row, White has to specifically get to the 3-point before he's in a position to jump. With a gap, White is ready to jump whenever he enters.
Filling in the gap is usually right even when Black has to take some risk to do it. Here there's no risk involved, so filling the gap should be clear.
HI, What about 8/7(2) 10/9 22/21 which duplicates 5's on white escaping or hitting black on 22 point? Without doing the math fair chance that White will leave a shot or at least give a bigger gap to squeeze black back checker out to come round and complete a full 6 prime...
I have to add that context matters, of course: if her 2pt blot is covered then making solid 5-prime becomes 0.080 error. Safetying our 2 blots becomes the best play.
Last edited by deh; 05-30-2018 at 06:40 PM.
Reason: add