FOX Pitchtracker’s Strike Zone is Brutal
Along with all the whirring, buzzing, booming effects and that incredibly annoying bar halfway down the top of the screen, Fox is using a high-tech feature called the “pitchtracker” occasionally during broadcasts that shows dots for each pitch around a box signifying the strike zone. It looks like the same one that has been used for Blue Jays broadcasts all year, and it’s only now that I’ve been objective enough to notice that it is ridiculously inaccurate. Almost every outside pitch looks like a horrible call by the umpires, and the broadcasters are constantly making excuses for them. Sometimes a pitch is called a strike and it looks like it’s half a foot off the outer edge. It’s fueling the fire for complaints about the umpiring of games, but really it’s the system to blame. Whoever set it up didn’t do some basic research into displaying an accurate strike zone.
The first problem is it’s shape. Sorry, the strike zone does not look like Ted Williams’ classic one any more. No umpire in the world calls a strike as high as dictated by the rulebook, and they give a couple inches off the plate. If you want to see the real strike zone, check out John Walsh’s measurements for a general idea. I’m actually starting to think that Walsh might have calculated a very slightly-too-large zone, but regardless it’s not the high, narrow box that is shown on the broadcasts (or even the slightly more squashed ones that are seen on the gameday program). It’s not that umpires are making “mistakes” to the side by a couple of inches, but that it is universally accepted that the real zone in slightly smaller vertically than the rulebook and to compensate is slightly wider.
To test the graphic on TV against the pitch f/x data, I rewound a few at-bats using TIVO and compared it to where the pitches were actually going. Here’s an at-bat that they featured between John Fogg and Eric Byrnes in the top of the 6th of the final game of the NLCS:
The yellow line is the average strike zone as determined by statisticians and called by umpires. It’s about 2 inches to each side of the plate and slightly above the knees and below the letters. The blue box is the rulebook strike zone. The red line is my estimate of where FOX had it’s strike zone set based on the broadcast. Vertically it’s consistent, but the width of the strike zone they use is insane. The announcers even called the third pitch “paint” because it was outside. According to the width of the real strike zone, all of those pitches were over the plate, but that particular pitch was a strike because it was the only one that caught the bottom edge of the strike zone.
Notice that their zone is about three inches narrower than the plate on either side (which is 10 inches wide), and that’s not even considering the standard inch or two off the edge of it that umpires give. Maybe they’re not including the width of the ball? But even that would only account for about half of the discrepancy. The zone is so narrow the ball is very rarely thrown inside it. For example, the Torrealba home run from the Rockies series was a mistake that ended up almost right down the middle, yet the pitchtracker shows it on the inside corner.
Here’s another example that includes the vertical height of the zone as well:
This is Troy Tulowitzki’s strikeout just before Torrealba’s crucial home run, which FOX showed in its entirety on pitchtracker. Matching their strike zone to the real one shows much the same results as the previous example (and clarifies the top edge). The first pitch was shown as just off the top corner, and so gives an idea of how high the strike zone they’re using is (I’m guessing it’s just below the letters). The third pitch (that Tulo fouled off) was shown as being right on the edge of the strike zone, which confirms that the outer edge they’re using is substantially inside even the edge of the plate. The final strike to retire Tulo was clearly a strike, but shown on FOX as being a terrible call by the umpire.
It would be one thing to blindly call the rulebook strike zone even though that is understood by players and umpires not to be the real one. But the current TV broadcasts use a strike zone that is even narrower than that, and makes any calls towards the outside of the plate look terribly wrong. From what I’ve seen, despite some eccentricities the umpires are actually consistently accurate to within a couple of inches, and the system that the major TV broadcasts are using right now is set so poorly it is misleading, and making both the umpires and the pitch tracking systems look bad.
It’s sad, really. As I’ve tried to show on this blog over the last few weeks, there are some pretty amazing and intuitive things you can show about what a pitcher is doing during a game or how the game is being called using this data. But instead of some real analysis we get another box cramped into the broadcast window that is useless and wrong.