Whiff Rate
Swings that miss, out of all swings.
What it actually is. The share of swings that missed entirely.
What a scout reads off it. The purest measure of bat-to-ball skill on the hitting side and of stuff on the pitching side. It is different from strikeout rate, which mixes in how often a hitter swings at all, and it is the number to look at when a hitter's contact suddenly changes.
Batter's Eye: look up anything in baseball