Joe Mauer has taken it to the haters, the doubters, the cynics. He has proved beyond a reasonable doubt that he was not the villain of the Twins' four straight losing seasons.

This year, he's producing the worst numbers of his career, and the Twins are winning.

Mauer is not a franchise-damaging culprit. He's a pleasant, well-paid bystander.

Mauer's recent history and current season speak to the complexity of winning Major League Baseball games.

Because he makes $23 million a year, he carried much of the blame for four straight 90-loss seasons. That was oversimplification.

The Twins lost mostly because they had flawed rosters filled with ineffective starting pitchers. Mauer's decline in power and production made bad teams look even worse, and his contract attracted anger the way bug zappers attract mosquitoes.

Now that Mauer is batting third for one of the better teams in baseball and is getting clutch hits and producing a surprising number of RBI, saying that he is doing his job would be another oversimplification.

He's actually producing the worst numbers of his career, ones that in a better lineup would lead to him batting second — or sixth. Because he is Joe Mauer and because the Twins are desperate for the comfort of the occasional quality at-bat, he continues to bat third, a spot that usually features power hitters, a demographic to which he has not belonged in six years.

Mauer had an on-base percentage of .323 and a slugging percentage of .363. Both would be career worsts if they don't improve markedly by the end of the season, so of course his OPS (on-base-plus-slugging percentage) is by far the worst of his career, at .686.

How unimpressive is that number?

Remember when Mauer won the MVP in 2009 with a remarkable combination of power and plate discipline? His OPS that season was 1.031.

That season, Mauer's current OPS would have ranked him not only behind Young Joe Mauer, but behind Jason Kubel, Justin Morneau, Michael Cuddyer, Denard Span, Joe Crede and, get this — Jose Morales. That season, Mauer's current OPS barely would have edged Brian Buscher and Brendan Harris, who never proved they could consistently hit big-league pitching.

On the 2015 Twins, Mauer's OPS ranks behind Brian Dozier, Torii Hunter, Trevor Plouffe, Eddie Rosario, Oswaldo Arcia and Eduardo Nunez.

Mauer ranks behind five Royals regulars in OPS: Lorenzo Cain, Alex Gordon, Eric Hosmer, Kendrys Morales and Mike Moustakas.

Among American League first basemen, Mauer ranks 11th out of 12 qualifiers. He ranks 12th of 12 in WAR (the sabermetric statistic called Wins Above Replacement-level player.)

Mauer has saved face and won games by accumulating clutch hits. He's ranked third in the American League with a .411 batting average with runners in scoring position. He has produced 34 RBI, second on the team.

His clutch hits have temporarily obscured his inability to frequently drive the ball, a problem that was supposed to be mitigated with him healthy and not playing catcher.

Last year, the Twins' wishful theory was that playing first base would lead to fresher legs, more pop and more durability.

This spring, the wishful theory was that Mauer couldn't work out hard going into 2014 because of nagging injuries, that this would be the season in which fresh legs and a new position paid dividends.

Using OPS as an imperfect but reasonable measuring stick, Mauer is in decline for a second straight season, both seasons during which he has played first base.

In 2013, Mauer managed only 113 games, but he hit .324 with an .880 OPS. Last year, his OPS fell to .732. This year, it's .686. His decline since 2009, or even 2013, borders on unfathomable for a healthy player.

Mauer is 32. He has three more full seasons remaining on his $184 million contract.

Sometime in the next year, Byron Buxton and Miguel Sano will be batting near the top of the Twins' lineup.

Sometime in the next year, if he doesn't find a way to resurrect even his gap power, Mauer may become the Twins' least-valuable regular player.

Jim Souhan's podcast can be heard at souhanunfiltered.com. Twitter: @SouhanStrib • jsouhan@startribune.com