[jgorham]

A point no one has really made is that the BB is the one who is likely to have a 9 here. This is significant because he is in between 2 players (after GoT bets). If it were heads up he is much more likely to call a river bet with a 9, but as is he is likely to think that one of the other two players has him beat. And the way the other guy has played his hand (call call call) really seems like a draw, either spades or 78.

As for the flop call turn raise, this is a very good play IMO. Because even if hero has an edge in equity on the flop, it isn't that large. When the A hits and the BB bets and the middle player still calls, it is very likely no one has an A here, and GoT's equity edge is much larger (if the bet were raised to GoT this is an easy fold - not to mention his weak hand isn't exposed to check raises on the turn as it would if GoT raises the flop). Besides all that, this is a very disguising move - on this particular board his hand looks an awful lot like AK to the other two players.