The split-fingered fastball is the "it" pitch right now, but it is still rarely thrown by left-handed pitchers. Why is that?

After a chat with teammate Josh Hader, Tatsuya Imai adopted a similar grip on his fastball.

TORONTO(AP) — Mr. Splitty has returned. Showcased by World Series Game 6 starters Kevin Gausman and Yoshinobu Yamamoto, split-finger fastballs have been used for 6.8% of postseason pitches this year, ...