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What is a strike, anyway?

August 10, 2009

Neyer wants Pitch F/X data. Well, I aim to please. If anyone’s got an example of really awful balls and strikes calling — other than Rapuano’s, since I think we’ve been over him enough — I’m all ears. Or write it up yourself. I’m still looking for contributors.

At any rate, I noticed that the Pitch F/X data represents the strike zone as a plane. The plate, of course, has depth; the “area over the plate” is a prism, about a foot and a half deep. Here’s what the rulebook says:

The STRIKE ZONE is that area over home plate the upper limit of which is a horizontal line at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower level is a line at the hollow beneath the kneecap. The Strike Zone shall be determined from the batter’s stance as the batter is prepared to swing at a pitched ball.

It doesn’t say the front of home plate, or the back of home plate, or the middle of home plate. This indicates that the strike zone is a prism, and that going through any of that prism is a strike. If a breaking pitch clips one corner, that’s a strike. And that’s how I’ve always understood the strike zone.

Ah, but there’s a catch. The rulebook also has the following diagram to illustrate the strike zone:


In this, there is no indication that the strike zone is anything but a plane. Of course, it still doesn’t say that it’s the front of the plate or the back of the plate or the middle of the plate or wherever. Anyway, does anyone know where Pitch F/X draws its plane?

And don’t get me started on umpires who call balls and strikes based upon where the ball was caught.

7 Comments leave one →
  1. August 10, 2009 1:55 pm

    I had a brief rant about some bad umpiring last year.

    It was only one at-bat I complained about, though there were others in that game I was less than happy with. Couldn’t say whether Scott Bsrry is always that inconsistent or not, but here’s one example, anyway.

  2. August 10, 2009 2:41 pm

    Yeah, I had always thought that the strike zone was a home plate shaped prism about two and a half feet tall floating in the air above the plate. If any part of the ball intersected any part of the prism, it’s a strike.

    Maybe I was wrong, but I still like to imagine a Bob Gibson slider nicking one vertex to blow a guy away.

  3. August 10, 2009 2:50 pm

    I still think it’s a prism, and the rulebook text is correct. The people making the diagram just didn’t think it through.

  4. August 10, 2009 5:10 pm

    I agree; it’s definitely a prism. Great question about where the electronic systems place their planes. I wish I could help with an answer. This would have a tremendous effect on accuracy for a pitches with a large vertical break.

    As long as we’re on the subject of rulebook diagrams, here’s an off-topic factoid: the distance from bag to bag is greater from first to second than it is from home to first. That’s because second base is centered on the notional point of second base, whereas the other bases, including home plate, are entirely within the infield diamond.

  5. August 10, 2009 6:23 pm

    Of course, there is this alternative theory on the strikezone:

  6. Haaveilla permalink
    August 11, 2009 1:00 pm

    Two cases of really bad umpiring I’m thinking off (I wouldn’t mind writing about these, but English is not my mother tongue so it wouldn’t be anywhere as good as your writing I guess):
    -The pitch before Tino Martinez’s grand slam in the 98 world series (look at around 0:45 to see it). The pitch is right down the middle, yet the umpire calls a ball, you know what happened after that… You can also see Martinez blindly saying he thinks it was a good call, while it was a terrible call indeed.

    -Mike Winters baiting Milton Bradley and causing him to be injured.
    Story: | Video:
    Basically the home plate umpire called Bradley out on a called strike 3, then asked the 1b ump (Winters) if Bradley had tossed his bat towards him. Later Bradley singled, and while being around the bag, he asked the umpire if he had said yes or no. The ump then baited him, used some insults, and a SD coach killed his knee while preventing him from killing the ump.
    Good news is the umpire was suspended, which obviously proves that he did something way wrong, but it sucks that a player has to be injured so that the MLB takes action and reviews an incident.

  7. max permalink
    May 22, 2012 5:04 pm

    If it is a prism and i throw a high arcing pitch which comes down directly on top of the plate but passes throught the prism would that be a strike?

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