XGID=---b--E-CA--dDa--c-e-A--A-:0:0:1:54:0:0:3:0:10
Unlimited games. How should Blue play 54?
When your opponent holds your 3-pt, holding your own 9-pt is a good thing to do because it blocks sixes. This implies that the four here should be played 13/9. After that there is little to choose between 21/16 and 13/8. I always try to keep the rear checkers connected so I would vote for 13/8. XG agrees but it bis very close.
It might surprise you that 9/4, 8/4 is a bad error so remember, block those sixes.