Official Rule(s) Regarding Strike Zone

If you looked at the strike zone as a cube, except for its length up and down, any ball that touches any part of that cube would technically be a strike. So yes, if the ball touches the rear outside corner of the cube it is a strike.

Next problem is getting it called that way.  I'm not an umpire, but calling balls and strikes on close pitches has got to be one of the most difficult things in officiating. Those that are the best at it, still miss on many pitches. And people still argue when they are right.

I agree with PGStaff that technically the strike zone is a 3-dimensional object and that if any part of the ball touches any part of the zone, it's a strike.

But, even in MLB, a pitch that hits the front of the zone and then hits the ground will not be called a strike, and the umpire will be graded "correct" on the ball call.

And, from a practical standpoint in HS (and to some degree in college) how the catcher catches the ball can influence what we see (and, in some areas, what everyone wants called.)

I love the umpire term "it is a strike unless I am convinced otherwise" 

I’ll take a shot at answering your question,

Let’s look at the definition (OBR)MLB.com + NFHS

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.

That’s each batters stance........just to be clear, that is at a minimum of 18 different strike zones/ per game for up and down....

Now the definition for a strike- OBR MLB/NFHS

A STRIKE is a legal pitch when so called by the umpire, which—
(b) Is not struck at, if any part of the ball passes through any part of the strike zone;

And a Baseball:

The ball shall be a sphere formed by yarn around a small core. It shall be 5-5 1/4 ounces and have a circumference of 9 to 9 ¼ inches……(meaning the ball is about 3 inches wide)

(Notice that the Black part of the plate is not mentioned in the rules…….)

In higher baseball the black beveled edge is not even visible since it is buried below the ground. But most certainly at the levels of baseball below college and pro the black is considered part of the plate for the purpose of calling balls and strikes....

Part of it has to do with the fact that the black is a half inch wide and the baseball is 3 inches wide. So a ball passing over the black can also be “in the zone”....

The vast majority of umpires, players and coaches expect a minimum of a ball width on the edges of the plate to be called a strike......and due to the dimensions of the ball and plate that would be supported by the rule book…..so even tho the plate is 17 inches, the rule book with its “any part of the zone” comment seems to support it being called that way.     

I don’t have any insight into pitchfx other than I would love to use it as a training tool But I’d like to go over my method and philosophy of calling balls and strikes for you.  

Being an umpire is parts art and science....the science part is learning the rules........the art part is calling balls and strikes,...calling balls and strikes in the real game world is a skill..... and being judged by a black and white definition in the rule book can be a challenge.....what is written, isn't often what is seen out there behind the dish...... 

I have my own zone....

My zone is just what happens when I am behind the plate attempting to judge a 3 dimensional strike zone that changes based on the batters height.

If you can imagine an invisible floating column, 17 and a half inches wide that extends from a horizontal line at the midpoint between the top of the shoulders and at the lower level is the hollow beneath the knee cap. The zone is determined by from each batters stance as the batter is prepared to swing at a pitched ball....the strike zone changes for a 5'6" batter to a 6' batter......

All of this adds to each umpire having their own zone....even as we all try to adhere to the rule book definition. Given that, in games with umpires of my experience, you will get different zones...much of it based on such things as the umpires height, his stance and the quality if the catchers.....I have seen recently injured umpires behind catchers of dubious quality jump around like cats on a hot tin roof.....not surprisingly the zone was jumping as well......

I believe that most trained umpires do try to call the strike zone as described in the rule book. Going back on my training, again, I can tell you based on video proof, at a clinic that I paid to attend  and while being watched by a clinician, that I call the borderline pitch inside and low a strike, but the outside and up pitch a ball.....now that is defining "my zone" over the strict rule book zone....

Its a condition of the above factors....... but I keep working to refine my zone to fit into the rule book, but truth be told, I probably won’t ever get it book rule perfect.....

I hesitate to offer this statement since usually this is the child’s way out, but I will offer that it isn’t as easy as it seems or looks….

But I will guarantee you that I will keep trying to get better......I attend clinics every year, where I will get cage work in....and I get evaluated every year…..

Despite all our efforts, I feel there will always be some variance. If at any time I feel I am doing "good enough" and fail to work on refining my game......I will call it a career.......

Hope this helps explain my view…Calling a good strike zone is where an umpire makes his reputation and it is something I work hard on.........

Balls and strikes get you there, base work keeps you there.

piaa_ump - thanks for the complete technical explanation along with your description of how one actually goes about calling balls/strikes.  The part about the "black" is very interesting as I simply assumed it was part of the plate (I guess you have to tag the white part also to score).

Based on the legal definition of a strike, I would like to think that Pitchfx "calls" balls/strikes, specifically balls, based on where the ball passes closest to the strike zone within the described three dimensional space. 

I hopefully still have several years of watching my kids play and I can tell you there is a difference between "good" and "bad" umps when it comes to working behind the plate.  Thanks for putting in the work and I am certain it gets noticed by both the fans and the players.