Player Props (NHL)

[Rich Boy]

Ex. An NHL player averages 1 goal per game.

What would be the fair price for this prop

Player Over 0.5 goals
Player Under 0.5 goals

[IrishTim]

Assuming the expectation of 1 goal is accurate:

OVER 0.5 goals (-172)
UNDER 0.5 goals (+172)

[Rich Boy]

Any math to back this up?

[IrishTim]

Any math to back this up?

No I just took a stab in the dark

Read up on Poisson Distribution. The hard part is coming up with accurate predictions (i.e. your estimate of 1 goal). Pricing them with Poisson is easy (assuming the Poisson distribution is applicable to whatever you are looking at; I learned this lesson the hard way).