Frame game: Twins hoping Castro aids arms

Frame game: Twins hoping Castro aids arms

MINNEAPOLIS -- The concept of pitch framing is certainly nothing new, but over the last five years, it's become a measurable statistic to see how much impact a catcher has on his pitching staff in terms of getting strikes called on pitches inside and outside the zone.

The new Twins front office, led by Derek Falvey and Thad Levine, understands the value of pitch framing, and that is a major reason why the club signed Jason Castro to a three-year deal worth $24.5 million. Castro is coming off a down year offensively, but his defensive metrics stand out, and he should be a boost to a pitching staff that had the second-worst ERA in the Majors last year.

Castro had 96 more strikes called last year than expected, which was the fifth-highest total in the Majors, according to Statcorner.com. It's a big improvement on last year's primary catcher Kurt Suzuki, who cost the Twins 38 strikes. So even if the pitching staff mostly remains the same, it should benefit from Castro's receiving ability.

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"The whole idea of signing Jason Castro, a lot of it was measured on the impact of catching on a staff," Twins manager Paul Molitor said. "As we've learned more about how to quantify that, it's probably been a little bit of an undervalued position for guys that handle some of those types of things better than others. We thought that was a big piece in trying to at least start off a way of trying to figure out a way to pitch better."

To get a feel for how pitch framing is measured by Statcorner.com, the site tracks the percentage of pitches caught within the strike zone called a ball (zBall%) and the percentage of pitches caught outside the strike zone called a strike (oStr%). Catchers want a low zBall% and a high oStr%, which is a combination Castro excels at. Castro had the third-highest OStr rate and third-lowest zBall rate among primary catchers, so he's good at both skills.

With those statistics, Statcorner computes a runs above average (RAA) for each catcher, and Castro ranked as the fifth-best overall pitch framer in baseball last year with 12.8 runs above average. Suzuki was five runs below average, which is a difference of nearly 18 runs. In advanced statistics, every 10 runs is worth roughly one win, so Castro's pitch framing alone is worth nearly two wins.

"The goal at the end of the day is to try to help your pitcher keep as many strikes as possible," Castro said. "And to not do anything to take away from presenting pitches that are in the strike zone to the umpires that would lead them to believe that any given pitch is not a strike."

Castro, however, wasn't always considered a strong pitch framer, but he has worked to make it a part of his game. He was rated as a below-average pitch framer in both 2012 and '13 before making it more of an emphasis heading into '14, and he has since been measured as one of the game's best pitch receivers.

The Astros clearly valued pitch framing, hiring Mike Fast, who was one of the first to attempt to quantify the value of the statistic in an article for Baseball Prospectus in 2011. Fast had Houston's catchers work specifically on pitch receiving, including changing the angles in Castro's setup. Castro also credited manager A.J. Hinch, a former big league backstop and fellow Stanford baseball alum, for helping him with his framing skills.

"Pitch framing has come a long way the last couple years and has gotten more attention," Castro said. "It's something over the last couple years I've tried to refine as much as possible. I don't know if 'enlightenment' is the right word, but there was a focus on this new topic of pitch framing. I tried to get a better understanding of what works, what doesn't."

Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, follow him on Twitter @RhettBollinger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.