Jeff Niemann does not weigh 280 pounds, but he used to. When Peter King and I saw him pitch a couple of years ago in Indianapolis, King asked, “Jeez, who’s the defensive tackle on the mound?” By the following spring, however, Niemann had remade his body with diet and exercise; I literally didn’t recognize him, though at 6’9″, I should have had an easier time figuring it out. He now looks more like an NBA forward than an NFL tackle. I’m no carnival guesser, but I would have spotted Niemann at around 230, probably a bit low due to his height. This year, the Rays weighed him in at 260. The team’s trainers weighed every player as part of his physical, then rounded to the nearest five.

The problem, however, is that the Rays’ media guide still lists him at 280. So does ESPN was the only major source that has the correct weight, though it’s unclear when it was changed. That’s not a big deal if you’re just looking up some info on Niemann or any of the other players in the major leagues. However, if you’re trying to project player performance, it is a very big deal indeed. PECOTA, Baseball Prospectus’ projection system, uses height and weight as one of the components it uses in comparing players.

Nate Silver can explain this in far more detail, but PECOTA uses height and weight, though differently. Silver told me that, “height is more important for pitchers, while weight is more important for hitters.” There are obviously accuracy issues, but there is an internal consistency. Other systems vary in their use of player size. Dan Symborski’s ZIPS system doesn’t use height and weight information, in large part because of accuracy. He also points out that players often change over the course of their career, making us wonder exactly when Barry Bondsweight on was accurate. It’s worse with Kirby Puckett. Sean Smith, the creator of the CHONE system disagrees. “I use weight, but not height,” he told me. “I get it whereever I can get it, and with a player I know, I’ll change it if it doesn’t look right. Bartolo Colon at 185? I don’t think so.”

There’s long been a game of taking a little off the weight or maybe adding a little to the height. Without a draft combine-style consistency of measurement, and without any real reason to worry about accuracy, it’s almost become a joke within the game. Tim Lincecum is not 5’11”, and he probably isn’t 5’9″ either. Dustin Pedroia might be 5’9″-if he’s standing on his MVP award when you measure him. He recently admitted that he was 5’5″, putting him in Phil Rizzuto territory. Jim Edmonds at 6’1″ was guessed at as 5’10” by one writer.

On the weight side, it seems as if players are as sensitive about their weight as your wife is. Prince Fielder‘s listed 268 pounds is the most egregious, but he’s hardly the only example of… well, let’s call these optimistic changes to a player’s measurements. Daryle Ward came to Reds camp looking as if he was “pushing three bills” according to one observer, but he was listed at 248. Not important? When a player’s trying to make the club, who knows what might tip things over. Calvin Pickering, the Quad-A slugger, was listed at 275, but faced some weight discrimination when trying to bring his huge frame to the majors.

Most of the inaccuracies come not at the extremes, but in the middle. For pitchers, especially while being scouted, 6’0″ is much more preferable than 5’11”. Of course, if 6’0″ is good, 6’1″ is better, though I have doubts that Tim Hudson is either of those. That doesn’t make him any less of a pitcher when he’s healthy. It happens at the other end, where pitchers over 6’6″ have a tendency to stoop when measured. Randy Johnson has been listed as low as 6’9″ during his career, though it’s generally acknowledged that he’s 6’11”. Why would a taller pitcher do this? Well, before the Big Unit came along, name another pitcher who was that tall and achieved any measure of success.

Today’s sports climate is still one that favors bigger, stronger, and faster, sometimes too much so. While the goal, inscribed in all Olympic medals in the original Greek, is nice, it’s also created everything from BALCO to hundreds of little J.D. McCoys on the playing fields of America. The important thing to note here is that while height and weight are interesting and it would be nice to have more accuracy in reporting, this list-which of course gives the listed versions-is even more instructive:

Tallest Players

Jon Rauch 6’11”
Randy Johnson 6’10”
Chris Young 6’10”
Mark Hendrickson 6’9″
Jeff Niemann 6’9″

Shortest Players

David Eckstein 5’6″
Callix Crabbe 5’7″
Danny Herrera 5’7″
Jimmy Rollins 5’8″
Ray Durham 5’8″

Heaviest Players

Jeff Niemann 280
Chris Britton 278
Bobby Jenks 270
Eddie Kunz 265
Prince Fielder 260

Lightest Players

Danny Herrera 145
Luis Castillo 145
Seven tied at 150

Looking at those groups, there’s simply no pattern of tall or short, fat or skinny, that precludes success-there are All-Stars and scrubs on that list. We might be able to measure height and weight, but talent? That only shows up in the results. There’s no reason that players need to lie, or that teams need to help them.

Of course, I should talk-my driver’s license says that I’m 6’0″ and 200 pounds.

A version of this story originally appeared on ESPN Insider Insider.