http://wizardofodds.com/blackjack/appendix2.html
http://wizardofodds.com/blackjack/ap...9-1dh17r4.html
EV (not win percentage) of standing 9,9 vs. 6: +0.20
Probability of dealer 6 becoming 18: 0.11
=> Win percentage = 54-55%
The splitting case is a little trickier, since splitting 9,9 isn't like having two hard 9's.
EV (not win percentage) of splitting (noDAS) 9,9 vs. 6: +0.35
EV of one-card 9 vs. 6 = +0.18
Probability of tying dealer 6 estimated by comparing dealer 6 with dealer 9:
at 17: 0.12*0.12 = 0.014
at 18: 0.11*0.10 = 0.012
at 19: 0.12*0.36 = 0.041
at 20: 0.11*0.12 = 0.013
at 21: 0.11*0.06 = 0.007
=> Total tie percentage is about 9%
=> Win percentage = 54-55%