Prospectus Today: Joe Mauer

The Joe Mauer Express appears to be steaming down the tracks right now. The 21-year-old Twin has been named the game’s top prospect by both Baseball Prospectus and Baseball America, one of those rare confluences of agreement between the two that mark a player as a future star. ESPN.com had him on their main baseball page on Tuesday, and Peter Gammons wrote glowingly not only of Mauer’s skill, but of the high opinion in which the young catcher is held.

I think Mauer is currently a good baseball player. He’s shown offensive and defensive development in his three professional seasons, and while I still think the Twins should have taken Mark Prior in 2001–how different might their two playoff losses have gone with the big right-hander?–clearly it’s not like they ended up with a bum. Mauer is going to eventually be a productive left-handed hitter; comparable to Mike Sweeney, with maybe a bit more power and patience.

I just don’t agree that Mauer is a future star behind the plate, and it has everything to do with his height. Mauer is listed at 6’4″, and people that height or taller just don’t have long, successful careers at the catching position. I mentioned this in the Top 50 Prospects Roundtable, and in fact used it to argue against Mauer’s selection as our #1 prospect.

Here is the complete list of 6’4″ (or taller) catchers who have accumulated 200 or more career at-bats, courtesy of the Sabermetric Baseball Encyclopedia:

                   EqA   AB    AVG   OBA   SLG    HT
Tom Haller        .282  3935  .257  .340  .414   6'4"
Jim Pagliaroni    .279  2465  .252  .344  .407   6'4"
Eddie Taubensee   .263  2874  .273  .331  .430   6'4"
Mark Bailey       .263   949  .220  .337  .337   6'5"
Fran Healy        .258  1326  .250  .329  .350   6'5"
Billy Bryan       .253   968  .216  .284  .395   6'4"
Jody Davis        .252  3585  .245  .307  .403   6'4"
Johnny Edwards    .251  4577  .242  .311  .353   6'4"
Sandy Alomar Jr.  .249  4126  .275  .311  .414   6'5"
Bob Tillman       .249  2329  .232  .300  .371   6'4"
Glenn Borgmann    .249  1294  .229  .325  .304   6'4"
Larry McLean      .248  2647  .262  .301  .323   6'5"
Ben Davis         .246  1319  .241  .313  .368   6'4"
Jamie Quirk       .239  2266  .240  .298  .347   6'4"
Dan Walters       .235   273  .234  .281  .348   6'4"
Jack Boyle        .234  4222  .253  .315  .327   6'4"
Haywood Sullivan  .233   851  .226  .312  .318   6'4"
Bobby Hughes      .230   319  .238  .287  .392   6'4"
Mark Parent       .228  1303  .214  .268  .375   6'5"
Bob Melvin        .224  1955  .233  .268  .337   6'4"
Paul Casanova     .222  2786  .225  .252  .319   6'4"
Tom Egan          .222   979  .200  .266  .299   6'4"
Andy Allanson     .221  1486  .240  .283  .310   6'5"
Joel Skinner      .213  1441  .228  .269  .311   6'4"
Sandy Martinez    .212   558  .233  .286  .337   6'4"
Chris Krug        .204   214  .192  .245  .290   6'4"
Marcus Jensen     .200   343  .184  .287  .289   6'4"
Marc Sullivan     .172   360  .186  .236  .258   6'4"

That’s everyone. The best tall catcher in baseball history is Tom Haller, and while Haller was a good player, no one is pushing his Hall of Fame candidacy. Eddie Taubensee? Jim Pagliaroni? Sandy Alomar Jr. is up there, and no one would wish Alomar’s career, with its many DL stints, on a young player.

The reasons why tall catchers don’t succeed would seem to come down to physics. Folding and unfolding a big body 150 times a night, 140 nights a year, takes a toll on the knees and the back, and a tall player already is putting a lot of stress on those areas. So either the tall player is a good enough hitter to move to another position, or he’s not.

If Mauer’s bat develops as his proponents expect, he’s not going to remain a catcher deep into his career. That’s where I think the Sweeney comparison comes into play. (That, and Nichols’ Law of Catcher Defense, which will probably take some chunks out of Mauer’s defensive reputation along the way. The law states that a catcher’s defensive reputation moves in the opposite direction of his batting performance.) I can see Mauer moving out from behind the plate as early as 2006 or 2007, with an eye toward sustaining his offense and keeping him healthy.

That won’t make him a bad player, but a .300/.370/.490 hitter has a much different value as a first baseman than as a catcher. The hype over Mauer is largely predicated on his being a backstop. Based on what we know about tall catchers, I don’t see his career progressing that way. He’ll either be a good defender whose bat won’t support a move–Joel Skinner, say–or a good hitter whose bat dictates a move.

I’d love to be wrong about this, because there’s nothing like seeing the start of a Hall of Fame career, and it’s really no fun being the wet blanket. But history is history, and projecting Mauer to have that kind of success as a catcher bucks all the evidence we have that 6-foot-4 catchers don’t end up as immortals.

In the short term, I’m probably even more skeptical. Mauer is 20 and has just a half-season of experience above A-ball. He hit for a high average and showed good plate discipline last year, but his power just isn’t there yet; it isn’t close. I think Mauer is going to spend at least part of the ’04 season back in Triple-A, and not only do I not think he’s going to be the Rookie of the Year, I don’t think he’s going to get any votes.