calculating fair odds (w/ push)

[jojo85]

Probably a stupid question with a trivial answer, but say the total for a (tennis)game is 20 and you expect it to go under with probability .5, over with probabilty .375 and push with probability .125.

Whats the right calculation for fair odds on the over/under?

Any help is much appreciated!

[Justin7]

Under odds are 500/375 * -100 = -133

[jojo85]

thanks justin