Prop pitch isn't hard to understand, if you run a search there are bunches of threads about it.
The stock answer is: A longer prop with a smaller pitch will give you better thrust/torque and a smaller prop with a heavy pitch will give you more speed. When you look at 3-D pilots props your going to find some long props with very light pitch.
It's still a testing required thing to find the prop that will fly the plane the way the pilot likes, there is no magic number or one size fits all, it's up to the pilot to find the prop they like.
I like my planes to fly slower but have shorter take offs and better virticle thrust so I tend to run longer props with smaller pitch. This thinking works most the time but I have some plane engine combos that just fly better with a bigger pitch.
I think that in the tower catalog they have props listed for 3-D, sport and pattern for the APC props. If you look at that you should see the pitch is different for the same size prop.
You can't just buy one size and think it's the perfect prop for the engine plane combo you have.
Buy a few and test to see what you like. It turns into a long day but it can be fun and an eye opener.
Gene