Best lefty off all time? My vote is Koufax!

[Aquarian Sports Cards]

from MLB.com

"The formula

(H - HR)/(AB - K - HR + SF)
Why it's useful

BABIP can be used to provide some context when evaluating both pitchers and hitters. The league average BABIP is typically around .300. Pitchers who have allowed a high percentage of hits on balls in play will typically regress to the mean, and vice versa. In other words, over time, they'll see fewer (or more) balls in play fall for hits, and therefore experience better (or worse) results in terms of run prevention. The same applies for batters who have seen a high or low percentage of their balls in play drop in for hits.

That said, skill can play a role in BABIP, as some pitchers are adept at generating weak contact, while some hitters excel at producing hard-hit balls. For example, Clayton Kershaw finished the 2019 season with a lifetime .270 BABIP allowed, while Mike Trout ended the campaign with a career .348 BABIP."

My Thoughts:

The all-time leader of BABIP for starters over 1000 innings is Babe Ruth at .241, 2000 innings Andy Messersmith at a slightly higher .241, 3000 innings Catfish Hunter at .243 Those are all fine pitchers but none of them are in the running for all-time greatest status. So clearly BABIP, even to the degree it is controllable, isn't a perfect stat either.