Baseball Savant - What's the Sweet Spot?

The theory to test would be if hitters who hit it right back at the pitcher the most have a higher than average batting averager o p s. So i did a little baseball savant browsing and tried to figure out what exactly are the characteristics of a batted ball that could potentially hit the pitcher. And so just by looking at various vites, i determined that roughly between negative three and positive three degrees horizontally, and then roughly between four degrees and eight degrees vertically, that is the sweet spot. We don't want pitchers to get hit by line drives but this is roughly what leads to a bad abalv that could hit a pitcher.