I love using this chart during practice, and having the kids know that this is what we use in order to replicate velocity. It's a true scientific approach to practice, and shows that you take into account these things even when it may seem like you're just throwing BP as usual. This chart is extremely easy to follow. I always keep a copy of it down at the field in order to set the portable mound up to take live reps. Using this will give your hitters a true representation of game velocity even if you can't create the velocity from distance on your own.