So heres the question of all questions. How in gods name do they measure the home runs that are hit in various staduims? Is it a measure of the trajectory and ball speed leaving the bat? Is it measured from the plate to the place it lands? The horizontal distance it travels? The horizontal distance it would have traveled if the stadium weren’t in the way? And once the supposed measurement is taken, how do they acurately know how its done? Two balls landing on the same bleacher seat wouldn’t necessarily land in the same place if you were measuring the theoretical distance to the ground. How do they even it out for all the ballparks? I need help on this one!
I hate it when people give such enticing titles to boring posts!
This has always bothered me too. I do know that there is some company which MLB has hired to determine how far the ball would have carried, if there were no stands and the field was level, if the ball’s trajectory hadn’t intersected the bleachers. They figure the distance for each seat in the outfield, a subjective, arbitrary distance, but one which can be used a yardstick to compare different homers.
A line drive home run would travel farther than a towering shot, which would drops almost straight down. So any so-called measurement is pure conjecture.
The only solution I can see is to put up two screens of lasers (Like those virtual golf games where you actually hit a golf ball through these screen into a back drop where a computer projects your “ball” down the 16th at Pebble Beach). You could then measure the trajectory and speed, factor in the wind and, voila, a more accurate measurement.
But then what do you do when Mark McGuire starts clearing your lasers?
Let’s see now. For the most part it is just a number that they tell the fans. It is not, I do not believe, an actual record that is being kept, at least not usually.
So, most ballparks have measurements from homeplate to that part of the fence, left, center, right. When a homerun is hit, someone watches where it goes and probably estimates based on the measurements to the various areas. Then they probably add depending on how many rows it went up.
Example: Let’s say center field in a certain ballpark is 400’ and the distance from one set of seats to the next is 2’. If Unca Mark hits one to dead center and it goes 10 rows back, then they would probably annouce he hit it 420’, however since 420 is such a nice number, they might fudge it and say 418 or 421 or something.
Not really sure, but why would they pay tons of money for laser measuring equipment just to tell how far someone hit the ball?
Jeffery (Nephew of Unca Mark)
It is merely a measure of horizontal distance, and often an estimate. They just measure/estimate how far it was from home plate when it landed. In some cases, where the ball hits an obstruction, they estimate the trajectory and claim it would have gone x feet if it hadn’t hit.
There’s no need to be accurate since HR distance isn’t anything more than a sidelight. As long as the ball is over the fence (or, rarely, that the batter manages to make it to all four bases before the other team gets to the ball), its a home run. Distance is just to impress the rubes. 
Actually, it is somewhat subjective, but probably a close estimate. ChiefScott is right in that a company was hired to aid in the process, IIRC it was IBM. A grid was created for each stadium. The grid coordinate for where the ball landed is fed into a computer along with the trajectory information (don’t know the exact breakdown but it’s some variation of “high, medium, low”. This is the subjective part). The computer then calculates the estimated distance.
BTW, Jeffery, the numbers are recorded. At the end of the season you can get information on the longest HR’s of the year in MLB or by stadium.
The overwhelming majority of people have more than the average (mean) number of legs. – E. Grebenik
Oops, should have stated “The computer then calculates the estimated distance the ball would have traveled unobstructed over level ground.”
Of course they’d never have laser screens to measure home run distances, Jeff. I just used that as a way to illustrate that there is no real way of accurately measuring the distance of a home run – well, no cost efficient way.
MLB has tapped in to another statistic which they can provide to attract a new, younger fan. Check out batting practice in any stadium Mark Mcguire appears. In St. Louis’ recent three-game series vs. the Phils in Philly, the local papers reported that extra police had to be brought in to keep the stairs clear DURING BATTING PRACTICE. An usher was quoted saying she normally deals with 10-15 people in the left field upper deck during the GAME. If these folks want to see the big homers, MLB’ll give em the stats they want.
Now, a 420-footer which drops just over the left center field fence counts the same as a 500-footer blast to the upper deck, but which is gonna make Sportscenter’s opening?
dammit!!! It’s M-c-G-w-i-r-e.
Mark McGwire. McGwire. Get it right!
I don’t know who first said “everyone’s a critic,” but I think it’s a really stupid saying.
No, its Unca Mark.
Jeffery
Doc, I figured that they recorded those distances, they record everything. But my point was I was not aware of a record for it. That is 70 HRs in a season is a record, 751 HRs in a career is a record. 515 ft HR is not a record that is in the books so to speak.
Jeffery
You don’t follow sports much do you?
They supposedly do have official measurements for different parts of stadiums, but it still is all a bit of a sham.
It still comes down to one guy sitting many feet away in the press box, consulting a chart, and saying, “Hmm, looks like it landed there.”
They even give distances for home runs at Wrigley Field that bounce out on to Waveland Ave. How does the guy in the press box know where it landed?
And, yes the length of a home run is not an official record. But please the alltime home run record is 755, not 751. Let’s all give Hammerin’ Hank his due.
From reading the papers and listening to Gary Cohen on the radio, I get the impression that these numbers are picked arbitarily, based roughly on a grid they have. How accurate can they be if Tropicana Field had its fences 15 feet closer than the listing on the wall? Even Fenway Park’s Monster is wrong, based on accurate calculations by computers (It’s 9 feet closer than the number on the wall). In the second game versus the Yankees at Shea, Mike Piazza hit a shot that hit the top of a tent set up over the fence for various bigwigs. Gary Cohen believed the resulting estimate, 480ish feet, to be on the low side. Usually, it’s the PR director who estimates the shot. Usually, that means the opposing team gets the short end of the stick, so to speak.