We already know he's this season's best rookie, the leading candidate for American League Most Valuable Player, and one of the best 20-year-old major leaguers ever. But is Mike Trout having one of the best seasons by a non-pitcher of any age or experience level in major league history? Consider this: Through Monday, Trout had been on the major league roster for 101 games and accumulated 8.4 wins above replacement according to Baseball-Reference's WAR statistic (bWAR). Project that total over the Angels' remaining 40 games (including Tuesday night, when he went 2-for-4) and you get 11.7 bWAR. Here are the greatest non-pitching seasons in history according to that measure, which combines offense, defense, and baserunning:
Based on his current projection, Trout would rank sixth on the above list, a tick ahead of Barry Bonds' best, chemically-enhanced seasons.
Of course, that's just one statistic. Baseball Prospectus's Wins Above Replacement Player (WARP) is more muted. Trout leads the majors in both statistics by a fair margin over fellow centerfielder and National League MVP leader Andrew McCutchen of the Pirates, but WARP has him at just 7.0 wins above replacement, which projects out to 9.8 WARP over the full season. That merely gets him into the top 40 non-pitching seasons since 1950 (which is as far back as WARP has been calculated). FanGraphs' WAR (fWAR) skews closer to Baseball Prospectus' numbers, with Trout at 7.4, and projected to 10.3 fWAR, which would put him around 65th all-time.
Of course, for a 20-year-old rookie to even have the 65th best non-pitching season in the 142-year history of the major leagues is incredible. For example, just using Trout's bWAR through Monday, here are the greatest seasons by a 20-year-old in major league history (not counting deadball-era pitchers, who tend to dominate lists based on cumulative total-value stats like this one):
That's 101 games of Mike Trout against full seasons by the other four, and Rodriguez is the only non-pitcher ahead of him on that list. Looking at rookies (using the current definition), again with pitchers included from the liveball era (1920 to present) only, we get this:
Again, 101 games of Trout against full seasons from the other two, and he's essentially already equaled Allen's season per bWAR. WARP, meanwhile, has Allen at 9.5, Rodriguez at 8.6, and Gooden at 8.1, while Trout projects to 9.8. Given that, it's hard to deny that Trout is in the midst of what could prove to be both the greatest season by a 20-year-old and greatest season by an official rookie since the end of the deadball era (and ever by a non-pitcher). The question is where his season will rank without those qualifiers.
A quick conversation with Colin Wyers, Baseball Prospectus' director of statistical operations, confirmed my suspicion that the difference between Trout's value per bWAR and the other measures is bWAR's opinion of his fielding. Per Wyers, WARP and fWAR, which use Fielding Runs Above Average (FRAA) and Ultimate Zone Rating (UZR), respectively, are "mildly fond" of Trout's fielding, crediting him with around five runs saved. Defensive Runs Saved (DRS) the fielding statistic used by bWAR, by comparison, credits him with around 17 runs saved, more than three times that of the others. With DRS being the outlier, it seems like it should be eliminated, but DRS is the statistic popularized in John Dewan's Fielding Bible books, which are considered among the most accurate assessments of player defense available.
Maybe we can tone down that DRS rating and split the difference a bit, but splitting hairs over Trout's clearly outstanding fielding so as to pin down a theoretical evaluation like wins above replacement is to miss the forest for the trees. Let's step back for a moment and consider what Trout is actually doing on the field.
Trout is doing three things that are rarely found in combination: he's hitting for a league-leading average, hitting home runs at a 40-homer pace* (over 162 games), and stealing bases at a 60-steal pace. Those three in combination allow us to create an impressive series of exclusionary lists. For example, Trout won't go 40/60 this season because he spent April in Triple-A, but no one has ever had as much as a 30/60 or 40/50 season before, and only two have ever gone 30/50: Eric Davis in 1987 and Barry Bonds in 1990. Trout is on pace for 33 homers and 54 steals, which would make him third on that list. Bonds' .301 average was the higher mark of the two. If Trout hits .195 or better the rest of the way (assuming his season rate of at-bats per team game persists), he'll finish above .301.
Similarly, only two players have ever had so much as a 30/20 season while hitting .340 or higher (Trout is at .344), and both, Ellis Burks in 1996 and Larry Walker in 1997, did that while playing their home games at Coors Field during its late-'90s number-boosting peak.
Let's make it simpler. Just four players have ever stolen 50 bases with a success rate of 90 percent or better: Jerry Mumphrey in 1980, Tim Raines in 1987, Barry Larkin in 1995, and Willy Taveras in 2008. Trout, despite being caught stealing for just the fourth time all season Tuesday night (and the first time since June 3), has been successful on 91 percent of his steal attempts this season. Mumphrey and Taveras didn't hit much in those seasons. Larkin and Raines did. Larkin won the MVP; Raines should have. Larkin's in the Hall of Fame; Raines should be. Trout belongs with Larkin and Raines.
How about this one: Trout is currently hitting .344/.407/.606 and has stolen 39 bases. Only three men in the modern era have ever hit .300 or better, gotten on base 40 percent of time or better, and slugged .600 or better and also stolen 40 bases in the same season: Ty Cobb in 1911, George Sisler in 1920, the season he set the since-broken single-season hits record, and Barry Bonds in 1996. Of those three only Cobb stole more than 42 bags.
You know what might be the most interesting thing about those lists? The only other player to make more than one of them is Bonds, arguably one of the handful of greatest non-pitchers ever to play the game, and it took him multiple seasons to do so.
Of course, Trout has plenty of time left in the season to slump and drop his average below .340, his on-base percentage below .400, his slugging below .600, his stolen base percentage below 90, or to fail to reach 30 homers or 50 steals due to a slump or injury, but part of what has made his season so spectacular to this point has been his ability to avoid both. He hit .324/.385/.556 in May, .372/.419/.531 in June, an absurd .392/.455/.804 in July, and has since "cooled off" to .307/.386/.600 in August. Oh, and by the way, in 20 games in Triple-A prior to his call-up, he hit .403/.467/.623 with a hit in every game.
Plus there's one other thing I haven't mentioned since getting past those advanced stats: his fielding. No matter how you want to quantify it, it's excellent. His production at the plate and on the bases combined with mere competence in centerfield would be MVP-worthy (see Matt Kemp's 2011 season), but he's better than competent, and