Clearly in the new modern era of all star games the main requirement is to play as little defense as possible. It has got so bad that commissioners are treating to cancel these meaningless games.
I can remember play these things under totals like 244 about ten years ago.
Even at a stupid number like 297 I just want no part lay up drill tonight.
I doubt one person on this planet has a big position on the under. Only big bets the books are taking is on buybacks from people that bet early.