Using PITCHf/x To Analyze The Strike Zone


In our first season covering baseball here at Sons of Sam HornIan York has been using PITCHf/x to analyze the strike zone and the way it is called in MLB. Here, we have collected his observations to get a complete view of the impact.

Despite the fact that the MLB rule book has a clear definition of the strike zone, the human element makes the zone imperfect. Ian looked at the imperfection of the zone and explored how it can affect the game. He also explored the strike zone called in a playoff game, and how one bad day at the office can affect a playoff race.

Each pitch has an effect on an at bat, but does the count also have an effect on the strike zone? Ian explored that to further show the effect that the human element has on the zone.

With the availability of PITCHf/x data, the effect that catcher framing is having on the game is easier to explore now than ever before. Ian also looked at Boston Red Sox catchers to see how the Sox may value framing.

There’s no one more important to the strike zone than the umpires themselves. It may surprise some observers, but the men in charge of the zone are quite consistent with calling it. However, there are some who are worse than others.

With over a month’s worth of data, Ian took some time to see if the strike zone was shifting, and did this once more with slightly more than a third of the season in the books. Ian also checked to see if the strike zone was having a larger than normal impact on struggling first baseman Mike Napoli as well as the effect extra strikes has on others.

With the 2015 regular season in the books, Ian took a looked at the strike zone throughout the year and displayed the new average zone.

Follow Ian on Twitter @iayork.