[ZootMurph]

First, they need to eliminate one more player to end play for the evening. Second, the side pot is at 300k. Finally, Matusow bets 450k into the 300k sidepot and he is the chip leader with over 4M at this point.

Taking these things into consideration, the majority of players would not even consider betting into that sidepot without a monster hand. Matusow could conceivably have TT, 99, 77, or even J8s or 86s. If he's bluffing at the sidepot, let him have it. But there is NO reason to believe he is bluffing at it when there is a player on the line to be eliminated to end the day. Since he would probably have pushed allin with AA or KK, and wouldn't have gotten involved in an allin situation with J8 or 86, then that leaves TT, 99 or 77 he's working with. You can probably rule out 99 and 77 as he may be up against a bigger set and would be happy to check down. Lastly, as chip leader are those 300k chips so necessary to his stack that he'd bet at it with anything less than top set? No, they aren't. It seems obvious from this thought process that he's on TT.