I wear a 10.5 in the M/L. You could easily fit an 11 in there as I don't have my toe ramp or toe strap extended all the way. I'd def go with the M/L with a 9.5.
yes definitely go with M/L for union. my first pair of boots was way too big for me (size 10.5) and the L/XL barely fit. The next season I got boots that actually fit me (size 9 haha) and my boots didn't even come close to fitting so I had to sell my Contact Pros.