For the Sun-Times

With exhibition games about to start and Cubs fans hoping young players will bring fast improvement, newly acquired veteran catcher Miguel Montero is poised to become an important part of the mix.

That Montero is expected to take over regular catching duties from Welington Castillo is partly the result of pitch-framing, where hot new metrics have shown increasing influence in front offices around baseball.

By traditional numbers — and even by pre-framing sabermetric stats — Montero doesn’t look like a huge upgrade. Castillo hit .237 with 13 home runs and a .686 OPS in 417 plate appearances for the Cubs last season, while Montero hit .243 with 13 homers and a .699 OPS in 560 plate appearances for the Diamondbacks.

When you turn to runs created, which crunches all a hitter’s plate appearances, hits, walks, hit-by-pitches, extra bases, sacrifices, stolen bases, caught stealings and double plays, Montero comes up at 4.0 runs created per game to 3.9 for Castillo. As listed at, a lineup of nine Monteros would have been about a tenth of a run per game better than nine Castillos.

Defense? Baseball Info Solutions lists Castillo at eight runs saved when compared with an average catcher; Montero was a minus-7. When you include offense, defense and baserunning in wins above replacement, Castillo was worth a 1.8 rWAR to 0.7 for Montero.

But even most advanced defensive metrics aren’t listing pitch-framing data yet, and that’s a game-changer. Modern pitch-tracking systems make it possible to compare pitches in and out of the strike zone and whether they’re called strikes. lists pitch-framing data at, and Montero comes in at the top of the list for 2014. There are a couple of different things to look at: the percentage of pitches caught outside the strike zone but called a strike (oStr%) and the percentage of pitches caught in the zone but called a ball (zBall%).

In a category where lower is better and the major-league leader was the Giants’ Buster Posey at 10.2, Montero was the fourth-best in baseball with an 11.0 zBall%. That means 11 percent of pitches caught in the zone were called balls. On the flip side, Montero was the best in baseball at having pitches outside the zone called strikes, with a 9.3 oStr%.

Castillo was at the opposite end of the list. Among 21 catchers with at least 7,000 calls, he tied for 19th with a 16.8 zBall% and was 21st with a 6.0 oStr%.

Overall, Montero got 180 more calls than an average catcher with his 9,525 opportunities, and Castillo got 183 fewer calls than an average catcher with his 7,903 opportunities. Translated to runs, Montero’s framing saved 24 runs when compared with an average catcher; Castillo was at minus-24.3.

With a metrics-aware front office, a difference of 48 runs is an attention-grabber, just the kind of thing to look for in adding veteran savvy to a youthful mix.