7 reasons why No. 7 belongs in the Hall of Fame

Selected by his hometown team with the first overall pick of the 2001 Draft, Twins franchise icon Joe Mauer debuted with Minnesota in 2004 and never wore another uniform throughout his 15-year Major League career. After officially announcing his retirement on Friday, there's no doubt that Mauer will go down as one of the greatest to ever wear a Twins uniform.
But five years from now, when he is eligible for induction to the National Baseball Hall of Fame, will he also go down as one of the greatest to ever play the game?
To commemorate the conclusion of Mauer's storied career, here are seven reasons why No. 7 should be voted into the Hall of Fame.
• Mauer is the only catcher to claim three batting titles, having paced the American League in 2006, '08 and '09. His .365 mark in the last of those three seasons represents the highest single-season mark by any primary catcher in modern history with at least 500 plate appearances.

• Mauer closed his career with a .388 on-base percentage, which ranked fifth among active players with at least 3,000 plate appearances behind Joey Votto, Mike Trout, Paul Goldschmidt and Miguel Cabrera. Among players who logged at least 5,000 plate appearances and spent at least 45 percent of their games behind the plate since 1900, Mauer's OBP ranks third behind Hall of Famer Mickey Cochrane and three-time World Series champion Wally Schang.
If Mauer had continued playing and made an out in every one of his next 1,050 at-bats, he would still finish with a higher career OBP than Hall of Fame catchers Johnny Bench, Gary Carter and Carlton Fisk.
• A total of 30 players have recorded at least six qualified seasons with a .400 OBP or higher since the Major Leagues integrated, and thus expanded the talent pool significantly, in 1947. Mauer is the only one of those 30 players to log even one of those seasons as a primary catcher, and he spent a majority of his time behind the plate in all six of those campaigns.

• Among that same group of players with 5,000-plus plate appearances and 45 percent of games behind home plate since 1900, Mauer's career 124 OPS+ -- a metric that takes a player's on-base plus slugging percentage and adjusts to the conditions of his era -- ranks 10th. Eight of the nine players above Mauer are in the Hall of Fame, with 1972 World Series MVP Gene Tenace being the only exception. Tenace, like Mauer, logged significant time at first base in the later years of his career.
• According to JAWS (Jaffe WAR Score system), a metric created by Jay Jaffe to evaluate Hall of Fame worthiness at a given position, Mauer ranks seventh all-time, behind Bench, Carter, Ivan Rodriguez, Fisk, Mike Piazza and Yogi Berra. JAWS takes a player's career wins above replacement (Baseball-Reference) and averages it with his seven-year peak WAR. Mauer's score is 47.0, whereas the average score of the 15 Hall of Fame catchers is 44.0. All six catchers ahead of him on the list are in the Hall of Fame, as well as the two behind him -- Bill Dickey and Cochrane.

• From 2004-13, the years that Mauer was primarily a catcher, his 44.7 WAR (Baseball-Reference) dwarfed all others at the position (minimum 45 percent of games at catcher), with Victor Martinez (28.2) and Yadier Molina (27.5) coming in second and third, respectively. Of all players, regardless of position, between '04 and '18, Mauer's 55.1 WAR ranks ninth, behind Adrián Beltré (81.9), Albert Pujols (79.2), Robinson Canó (69.2), Cabrera (68.8), Chase Utley (65.1), Trout (64.3), Votto (58.8) and Ian Kinsler (57.3).
• And even when looking at counting stats instead of rate stats, Mauer compares favorably to elite catchers of the past. Again, among those players with at least 5,000 plate appearances and 45 percent of their games as a catcher, Mauer is one of 10 with at least 2,000 hits -- and six are Hall of Famers. He accomplished this despite having fewer plate appearances than all of them except A.J. Pierzynski and Piazza. He's one of only five in that group to also have at least 400 doubles, joining Hall of Famers Rodriguez and Fisk, along with Pierzynski and Ted Simmons.