Betting vs. Prediction

A quick review of an important concept going into this weekend's Super Bowl:

The "point spread" for a football game is set at the level required to get equal numbers of bets on the two teams.

The spread is not the consensus opinion of expert observers as to the likely outcome of the game. The two are often similar, but the point spread is fundamentally about the behavior of bettors, not the prediction of outcomes.

This ought to be trivially obvious from the fact that you don't see anybody on ESPN taking the Patriots and giving the points. It's surprising how many people who make their living talking about sports can't seem to remember it.

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