Zach Putnam threw 20 pitches on Monday night, and 15 of them were splitters. Many were balls. The White Sox reliever walked all three batters he faced in the ninth inning of a tie game at Fenway Park. Dennis Eckersley, doing color on the Red Sox TV broadcast wasn’t impressed. In his opinion, Putnam “deserves to lose” because he was throwing so many splitters.

Results aside, was it a mistake to throw that many? Putnam has utilized the pitch 68.3% of the time this year — the highest percentage in baseball — and he boasts a 2.30 ERA, striking out 9.9 batters per nine innings over 25 appearances.

Extreme splitter usage isn’t unique to Putnam. Koji Uehara lives and dies by the pitch. Last season, Uehara had a four-game stretch where he threw 52 splitters and just six fastballs. (Broadcasting in Boston, Eckersley presumably knows this.)

I wasn’t able to ask Putnam about his outing, as he left town after the game to have his elbow examined. (He was placed on the disabled list with ulnar neuritis.) I did check in with his catcher, Alex Avila, and his pitching coach, Don Cooper. Both defended the split-heavy ratio.

“His fastball isn’t the reason he’s in the big leagues,” Cooper told me. “If we’re going to win or lose a game, it’s going to be on the split more often than not. His best pitch is a split. He’s been striking out a batter per inning, and he hasn’t been doing it with fastballs. His fastball is to keep hitters honest.”

“We did throw fastballs,” added Avila. “On the walk to Hanley (Ramirez) we threw a 3-2 fastball and almost got him looking, because I think he was thinking splitter. It really has nothing to do with the percentage of times you’re throwing it. The game, the player, the situation, dictates that, as well as what the the pitcher is comfortable throwing. He’s comfortable throwing his split.”