[adanthar]

For starters, here's what he probably doesn't have: a jack. If he called both the flop and the turn with it and managed not to raise on a three flush board, he's...not good. (It's possible he's got something like K [img]/images/graemlins/club.gif[/img] J, but unlikely.)

He might have a set or a flush. He might also have total trash (medium pair, two cards that he is planning to bluff with). Don't even think about a blocking bet; bet/raise/call is a good way to lose your stack - all of the bluffs are going to abandon ship on this card because you're not folding, and all of the big hands will raise big because you're not folding.

It's a lose/lose situation...unless you check. Which I do 100% of the time on this board, and then I call a big bet and beat his 75 offsuit that he would never have bluff raised with now.

PS: If he has a midpair, checking is also faaaar better. Do you see why?