I would say yes to the first question. If you bet on this and it was indeed a "B" loss, if Anthony is playing against the Raptors, I would bet them. But that's just me.
As for when the books close out bets, I would say that it depends on the books. I would guess that some books keep them open right up until the start of the game.
As for when the books close out bets, I would say that it depends on the books. I would guess that some books keep them open right up until the start of the game.