Joe Mauer's Historic Slump

This Joe Mauer thing is getting out of hand.  Not the vitriol aimed toward Mauer, I've gotten used to that.  His lackluster season is getting out of control.  Even in his down 2011 season, he managed an above-average OPS+ (only 102, but that counts).  In Mauer's first season as a full-time first baseman, he is having a disaster of a season at the plate.  Many theories have been proposed to explain this disaster, ranging from the always eloquent "Mauer sucks" on Twitter to Parker Hageman's more nuanced analysis a couple weeks back. 

Whatever the reason for Mauer's struggles, the fact remains that he is having what is easily his worst season, all while carrying the lightest defensive load of his career and making a ridiculous salary that I won't even mention in mixed company.  The frustration toward Mauer's poor performance and the curiosity about what is causing his poor performance is reaching a nexus.  Even those who defend Mauer at all times (myself included) are confused by his sudden and seemingly unexplained decline. 

Hageman's article makes some very valid points and does provide a prescription of sorts to help Mauer get back on track.  That said, Mauer may not be capable of following that formula if his ability has just starkly declined.  The concussion Mauer suffered last season has been served up as a possible explanation, but considering how cautious the Twins have been with Mauer in the past and how much emphasis has been placed on concussion awareness, you'd think that they would have already ruled this out. 

The simplest solution is that Mauer is going through a prolonged slump.  There are some indicators that point toward this explanation.  Mauer is currently hitting left-handed pitching like a guy who isn't an all-time great.  He is a career .293/.364/.383 hitter against lefties, far below his overall career numbers, but still respectable against same-sided pitching.  His .747 OPS against lefties would be 58th among all left-handed batters with at least 1000 plate appearances since 1961.  This season, Mauer is batting .208/.279/.208 with zero extra-base hits against lefties.  Yikes.

His BABIP against lefties is about 50 points below his career average, but that doesn't really account for the complete loss of power.  His strikeout rate against lefties has been gradually increasing since 2008.  It has spiked four more points in 2014, hitting 24.4%.  In addition, his walk rate against lefties is down five points since 2012.  His line drive rate is up, so he's making good contact.  He's just making contact far less often.  All of this is discouraging, but we are talking about just 86  plate appearances.  Again, this could be just a high-profile slump.  

His numbers against right-handed pitching are down as well.  His career line is .334/.421/.503.  He is currently hitting .286/.365/.395.  His BABIP is about 50 points lower than his career figure, but again, that doesn't explain the lack of power.  However, his ground ball rate is seven points higher than his career average.  He isn't getting the ball up in the air and he isn't fast.  More grounders, fewer fly balls, less power, less speed...  This is not a good combination. 

I didn't intend to point out the obvious again.  Everyone knows that Mauer is having a bad year.  We're experiencing it with every game.  It seems to be getting worse by the minute and I'm certain that Mauer is pressing.  Yes, Robot Mauer is capable of human emotion.  Since we can see this clearly, I'm more interested in the historical context.  What if Mauer never returns to the levels he established earlier in his career?  What if he doesn't get halfway there?  What if this is Mauer's new level of performance?

I shudder to think and I'm still optimistic.  That said, it would be pretty unprecedented.  I looked up every single player since 1901 who has provided 40 rWAR or more before age 31.  Mauer sat at 44.3 before this season, his age 31 season.  My search resulted in 97 non-active players.  Of those players, only 44 provided more than 20 rWAR from 31 to retirement.  Only 24 topped 30 rWAR.  Only 14 topped 40 rWAR and those are some of the best players of all-time.  I would argue that Joe Mauer is a Hall of Fame player (or I would have last year), but I'm not sure he belongs withe Rickey, Clemente, Cobb, Musial, Aaron, Mays, Ruth and other guys who you can identify by one name.

But, there are 26 players who didn't provide another 10 rWAR from 31 on.  Many of these are Hall of Very Good players like Dick Allen, Joe Torre and Ted Simmons (more on him later), but some are Hall of Famers like Ken Griffey Jr, Ron Santo and Duke Snider.  Those guys provided a lot more WAR before their 31st birthdays, so they have that on Mauer.  If you look at the five guys on this list with the lowest WAR from 31 on, it's clear to see why they fell apart:

1. Chuck Knoblauch (psyche)
2. Travis Jackson (knees)
3. Nomar Garciaparra (injuries)
4. Darryl Strawberry (drugs)
5. Andruw Jones (donuts)

But what of the catchers?  Could it be that Mauer is just beat up because of the demands from donning the tools of ignorance?  There aren't many catchers on this list.  In fact, Mauer would be one of eight players.  Of those eight, three are in the Hall of Fame:  Gary Carter (14.3 rWAR after 30), Mickey Cochrane (11.4 rWAR after 30), and Johnny Bench (11.1 rWAR after 30).  Two are likely to join them:  Ivan Rodriguez (18.1 rWAR after 30) and Mike Piazza (17.9 rWAR after 30).  And one probably should be in the Hall:  Thurman Munson (5.6 rWAR after 30, but he was sadly killed in a plane crash at 32). 

Of course, these guys all remained catchers after 30.  The eighth guy?  Ted Simmons, who I mentioned earlier. 

Simmons might be Mauer's closest comp.  Simmons was on a Hall of Fame trajectory through age 30.  He had provided the Cardinals with 44.8 rWAR, just slightly more than Mauer has given the Twins.  Mauer bests Simmons in batting average, OBP and OPS+, but Simmons was the more powerful hitter and he played almost 300 more games by age 30.  For the wisenheimers, Simmons beats Mauer in GIDPs, 185-137. 

Then, at age 31, Simmons' OPS+ dropped suddenly.  It plummeted from 140 in 1980 to 87 in 1981.  Mauer's OPS+ last season was 143 and through Tuesday, his current OPS+ is 87.  Creepy.  The major difference is that Simmons was playing his first season with a new team and in a new league.  Even so, he finished the season at .216/.262/.376, a batting line the most ardent Mauer-bashers wouldn't propose as his floor.  Simmons did bounce back to an extent from age 32 to 35, posting a combined OPS+ of 102.  This was much better than his age 31 season, but a far cry from his career mark at age 30 (127).

Simmons caught almost 300 games during those five seasons, while Mauer will catch zero.  I believe this makes a Mauer rebound more likely, but it also means he will provide far less positional value no matter how he hits.  Simmons is not in the Hall of Fame, but you can make a valid argument in his favor.  Mauer will need to greatly eclipse Simmons' production in his 30s to make his own HOF case.  Moving positions at 30 will be held against him, even if his hitting does mostly improve to previous levels. 

Will Mauer mix a good season or two in with some bad seasons like Simmons did, or is this two-month stretch a harbinger for the rest of his career.  Hopefully for the Twins, this simply a blip on the radar of a Hall of Fame career.

I have no clue what to think.  Looking at his numbers, I can see a slight rebound, but how much?  Is something wrong with Mauer physically?  Perhaps, but if so, no one is saying anything.  Have teams finally figured out how to master Mauer?  This seems to be the likeliest of all scenarios.  Which leads to one final question:  does Mauer have adjustments in his bag of tricks in what is generally considered the decline phase of an MLB career? 

In the end, that might be the only question that matters and we have no way of answering it right now.  Time will tell but hopefully we won't have to wait long for an answer.