How To Determine EV

Say two teams are playing each other. Who is playing and what they're playing? It really doesn't matter.

Team A is -140 and has a 60 percent chance of winning. Team B is +120 but has only a 40 percent chance of winning. Assume they're playing a sport that can't end in a tie.

First, we had to find the Decimal Odds for -140. Divide 100 into 140, and you get .714. Multipliy by 60 and you get 42.857.

A 60 percent win probability means a 40 percent loss probability, so you multiply 40 times 1 to get 40.

Subtracting 40 from 42.857 leaves 2.857. The EV is just about three cents to the good.

Could Team B also produce positive EV?

Team B's 40 percent win chance times 1.2 would total 48. Subtract 60 from that, and Team B would be a worse bet at negative 12 cents.

Team A would be a way better play in this instance.