Orioles director of pitching development Rick Peterson's "string" theory of pitching down in the zone

SARASOTA, Fla. -- Orioles director of pitching development Rick Peterson pointed to the brightly-colored string that was strung just above home plate in front of catchers as minor league pitchers threw their first bullpens of spring on Monday morning at the Buck O’Neil Baseball Complex at Twin Lakes Park.

"That's the .193 line," Peterson said.


Peterson, a former major league pitching coach with the A's, Mets and Brewers who is in his second season in the Orioles organization, loves to talk stats. And he uses data to give young pitchers quantitative reasoning for his teachings.

Monday was a perfect example.


Instead of just telling young pitchers to pound the strike zone, he's giving them reasons why. According to his major league data, batters who put balls in play in the bottom of the strike zone – from the knees down – have a batting average of .193.

So that string across home plate on Monday? Aim for it.

"What you're trying to present to the guys is that these are outcome numbers, but if we follow this process and pound the bottom of the strike zone, [the average is] .193," Peterson said. "And that's the major league data. What do you think it is in the minor leagues. I don't have the numbers, but I would think its .125 or .150."

He's given pitchers other facts to consider, namely the importance of the 1-1 count. The average major-league on-base percentage in counts that start 2-0 and 2-1 is .480. The average for 1-2 counts is .220.

"So the most critical count of all is the 1-1 count," Peterson said. "That's a 260-point swing. … So we're telling our catchers and our pitchers, we're not looking for backdoor knuckle sliders on the black on the 1-1 count. It's a low percentage strike. Let's throw a high percentage strike."