Golf Scorecard issue

Hi guys,

I am making a very detailed scorecard for golf. The thing is that I can't seem to find out how to have the average number of strokes for a given par. So some kind of formula that will look at the holes and see the par 3's (for example) and be able to average the scores for all the holes with that par. I am pretty beginner and was thinking about a COUNTIF formula or something?

I've uploaded a little sample of my scorecard for you to see what I'm trying to do. I hope it helps.

Thanks!