Let’s start by stating the obvious, or at least what should be obvious to anyone reading this at Baseball Prospectus: Joe Mauer is by far the most qualified player for the 2009 AL Most Valuable Player Award. You know it, I know it, even many enlightened sportswriters know it. Despite a few recent rumblings in the mainstream media putting forward a slew of other possibilities, most of them clad in the throwback uniforms of “run producer” and “winner,” Mauer’s numbers are so compelling that even Joe Sheehan has expressed little doubt that voters will get this one right in the end.

I, for one, am not so sure. Mauer’s case is so strong that even the law firm of Sebben & Sebben should be able to successfully argue it. BP readers can be easily wooed by Mauer’s commanding lead in EqA, VORP, and WARP-but those unlikely to sway many actual voters. However, it should be hard for even the casual fan to miss the fact that Mauer is currently leading the league in batting average, on-base percentage, and slugging percentage, clocking in at a robust .378/.449/.635 through Sunday’s action. The last time a catcher managed to win this “Slash Stat Triple Crown”, or SSTC, was… well, actually, no catcher has ever done that before. Only nine players have managed it in the last 70 years, seven of them corner outfielders or first basemen. Clearly, such production from a player at a premium defensive position is extremely rare. So how likely is it that Mauer will win the SSTC?

To get some sense of how likely Mauer is to keep his leads in all three stats, I’m going to stand on the shoulders of giants and appropriate the method Eric Seidman recently used to roughly gauge the chances of Albert Pujols winning the standard AVG/HR/RBI Triple Crown. Eric’s method was to look at Pujols’ current number in a given stat (say, RBI), use his updated PECOTA forecast to determine what his final RBI number is projected to be, and then apply a binomial distribution calculation to determine the chance that each other player competing for the title would wind up with more RBI than Pujols, based on their projection for the rest of the season. Summing these chances for each player and subtracting the sum from one approximates the percentage chance Pujols has of winning the RBI crown, while performing the same calculation for the other two categories and multiplying the three results gives a rough idea of the likelihood of winning the Triple Crown.

The charts below show similar calculations for Mauer in each leg of the Slash Stat Triple Crown. I’ve modified Eric’s method slightly to be even more pessimistic by calculating the chance that Mauer would drop down to the current level of his closest pursuer, not that player’s (lower) end of season forecast-essentially, what would happen if the player in second place continued at his current level. I did this mostly because of Ichiro; PECOTA is notoriously bearish on his ability to sustain such high batting averages, but for this purpose I’d rather assume that he can:

Slash Stat Forecasts
                Current    Ending
Player            OBP       OBP       % Chance of Rank Change
Joe Mauer        .449      .439       3.4% Drop to .420
Kevin Youkilis   .420      .412       0.4% Raise to .439
Total                             1 - 3.8% = 96.2% chance of winning OBP

                Current   Ending
Player            AVG      AVG       % Chance of Rank Change
Joe Mauer        .378     .364       30.5% Drop to .359
Ichiro Suzuki    .359     .349        4.6% Raise to .364
Total                            1  -35.1% = 64.9% chance of winning AVG

                Current   Ending
Player            SLG      SLG       % Chance of Rank Change
Joe Mauer        .635     .599        0.7% Drop to .572
Kendry Morales   .572     .551        0.0% Raise to .599
Kevin Youkilis   .570     .557        0.0% Raise to .599
Total                             1 - 0.7% = 99.3% chance of winning SLG

Likelihood of Slash Stat Triple Crown:  62% (96.2% * 64.9% * 99.3%)

With such large leads in each category, even using a slightly more pessimistic version of Eric’s calculation leaves Mauer with a 62 percent chance of winning the Slash Stat Triple Crown-the biggest threat, as expected, is Ichiro winning the batting title.

But does winning the SSTC ensure winning the MVP trophy? Given the checkered history of MVP voting, there are likely no guarantees. To get a better idea, let’s take a look at the 15 previous SSTC-winning seasons since the outbreak of World War II and how they fared with MVP voters:

Slash Stat Triple Crown Winners (since 1939)
                                                   MVP    MVP
                                  MVP  RBI  Team   RBI    Team
Player            Team      YEAR  Rank Rank Finish Rank  Finish  MVP
Barry Bonds       Giants    2004    1   17   2nd    --    --      --
Barry Bonds       Giants    2002    1    6   2nd    --    --      --
Todd Helton       Rockies   2000    5    1   4th     4    1st    Jeff Kent
Larry Walker      Rockies   1999   10   10   5th    17    1st    Chipper Jones
George Brett      Royals    1980    1    2   1st      --    --       --
Fred Lynn         Red Sox   1979    4    4   3rd     1    1st    Don Baylor
Carl Yastrzemski* Red Sox   1967    1    1   1st    --    --      --
Frank Robinson*   Orioles   1966    1    1   1st    --    --      --
Ted Williams      Red Sox   1957    2   10   3rd     5    1st    Mickey Mantle
Ted Williams      Red Sox   1948    3    3   2nd     8    1st    Lou Boudreau
Stan Musial       Cardinals 1948    1    1   2nd    --    --      --
Ted Williams*     Red Sox   1947    2    1   3rd     3    1st    Joe DiMaggio
Stan Musial       Cardinals 1943    1    5   1st    --    --      --
Ted Williams*     Red Sox   1942    2    1   2nd     4    1st    Joe Gordon
Ted Williams      Red Sox   1941    2    4   2nd     1    1st    Joe DiMaggio
*: Won Standard Triple Crown

Here we see each SSTC season, how the player ranked in MVP voting and in that season’s RBI counts, where the player’s team finished in the standings, and (if applicable) the actual MVP’s rank in RBI and his team’s finish. Since the conventional wisdom is that high RBI totals and playing for a division winner are given disproportionate weight by the voters, including those columns might provide some anecdotal evidence to that effect.

Of the 15 SSTC seasons listed above, only seven actually resulted in an MVP Award. The remainder had one thing in common: the SSTC winner’s team didn’t finish first, while the MVP’s team did. This certainly lends credence to the idea that MVP voters often look for the best player on the best team, rather than the best player overall. With the Twins struggling to gain any traction in the AL Central race, this may be bad news for Joe Mauer’s MVP chances. Interestingly, only twice did the MVP tally more RBI than the SSTC winner-perhaps winning is given more weight than driving in runs in the hearts and minds of the voters.

Recent members of this list may point towards more nuance in the selections of contemporary voters. Barry Bonds was able to overcome second-place finishes, pedestrian RBI totals, and a chilly relationship with the media to win MVP Awards in his two SSTC seasons-all he had to do was log a half-decade of otherworldly production. The bad showings by Helton and Walker, however, indicate that voters have shown themselves capable of looking beyond ballpark-inflated raw numbers. Brett’s 1980 season, when he flirted with .400, was the last SSTC winner in the American League, and a deserved slam-dunk for MVP voters.

On the other hand, the 1979 vote, with Fred Lynn finishing fourth, defies explanation. In addition to the three slash stats, Lynn paced the American League that season in EqA (.343) and VORP (82.9). His 39 dingers were only surpassed by Gorman Thomas, his 122 RBI placed a solid fourth in the league, and he won a Gold Glove in center field. But the voters saw fit to bestow the MVP on Don Baylor and his .313 EqA, earned while spending significant time at DH. Baylor did lead the league in RBI, and his Angels squad managed to win a weak AL West-albeit with three fewer wins than Lynn’s Red Sox, who finished third behind dynasties in New York and Baltimore. Brett and Ken Singleton also finished ahead of Lynn that year-defensible choices, those-but Don Baylor? I guess disco made the whole world crazy.

Yaz and Robby each won MVPs after pulling off the rare “Triple Crown Royal,” winning both the standard Triple Crown and the SSTC for their pennant-winning squads, although Yastrzemski deserves an asterisk for sharing the home run title with Harmon Killebrew. But Ted Williams, as usual, has a story all his own. At what should we most marvel? The fact that Teddy Ballgame led the AL in all three slash stats five times over a 16-year span, while fighting two wars? Or that he never won the MVP in any of those five seasons, despite also winning the standard Triple Crown in two of them? Each time, Williams was beaten by a player at a premium defensive position on a team that finished first in the standings. Losing twice to DiMaggio and once to Mantle is understandable, as is Lou Boudreau’s win as Cleveland’s shortstop/manager in 1948. But winning the Triple Crown in 1942 but losing the MVP vote to Joe Gordon? That had to sting. Williams won an MVP in 1946 when Boston won the pennant, and again in 1949 when DiMaggio was injured for much of the year and no single Yankee garnered enough support. But the message is clear-being the dominant hitter in a given season does not guarantee you any hardware unless you’re still playing in October.

If Joe Mauer stays reasonably healthy and productive for the next month, there’s little doubt he’ll have been the most valuable player in the American League. But that doesn’t guarantee he’ll be the Most Valuable Player. How productive his teammates are over the next month may have just as much say, whether we like it or not.