Trout's sophomore season may be best ever

Did you know that Mike Trout is in the midst of a historically productive season?

I want to talk about second-year players, and specifically, second-year hitters. There have been a lot of good sophomores across baseball this season: Bryce Harper, Manny Machado, Jean Segura, Andrelton Simmons, Starling Marte. And, of course, the best of them all: Trout.

By the time this season is over, it is likely that Trout will have put together the best season ever for a second-year major leaguer. Thus far, Trout is hitting .338/.435/.575 with 23 homers, 83 RBIs and 8.4 WAR (with 22 games remaining on the schedule).

Here's a look at the top 10 sophomore campaigns (for non-pitchers), as ranked by Baseball-Reference's Wins Above Replacement formula:

1. Rickey Henderson, Athletics (1980): 8.7

2. Snuffy Stirnweiss, Yankees (1944): 8.4

T-2 Mike Trout, Angels (2013): 8.4

4. Eddie Mathews, Braves (1953): 8.3

T-4 Ralph Kiner, Pirates (1947): 8.3

6. Joe DiMaggio, Yankees (1937): 8.2

7. Wade Boggs, Red Sox (1983): 7.8

8. Pete Reiser, Dodgers (1941): 7.4

9. Evan Longoria, Rays (2009): 7.1

10. Arky Vaughan, Pirates (1933): 7.0

That's a pretty interesting list. Six of these guys have been inducted into the Hall of Fame: Henderson, Mathews, Kiner, DiMaggio, Boggs and Vaughan. The rest were All-Stars at some point in their careers. Of those who were eligible to win Rookie of the Year in the previous season (after 1947, when the award was introduced), only Trout and Longoria actually won.

Two of the guys are still active, but let's look at Trout. I'm not going to compare Trout to the Hall of Famers. Yet. Certainly, he is an elite talent, but too many things can happen along the way for us to go ahead and include him in the Hall of Fame Class of 2033. (This is assuming, of course, that the baseball writers haven't stopped electing players to the Hall at this point.)

What about the rest of that list? Until Henderson came along, Stirnweiss had put together an incomparable sophomore season. In 1944, ol' Snuffy, who had been an All-American football player for the University of North Carolina, had a superb season as the Yankees' second baseman; the 25-year-old Stirnweiss hit .319/.389/.460, posted an adjusted OPS+ of 139, and led the league in runs, hits, triples, stolen bases and plate appearances. By any measure, that's a great season, but especially for a guy who had hit just .219/.333/.288 as a rookie in the previous campaign.

Stirnweiss followed up with an even better year in 1945 (8.6 WAR), leading the league in batting average, slugging percentage, runs, hits, triples and stolen bases. But that was his high-water mark.

After the war (not Baseball-Reference WAR, the actual war: World War II), when players were returning from service, Stirnweiss posted uniformly below-average offensive numbers and finished out his career as a part-time player for the Yankees, St. Louis Browns and Indians. Clearly, his numbers were helped by the watered-down level of player during the war.

In his second season, at age 22, Pete Reiser tore apart the National League, hitting .343/.406/.558 and finishing second in the MVP voting (to teammate Dolph Camilli). Reiser led the Senior Circuit in average, slugging, runs, total bases, doubles and triples. He put together another fine year the following season, although he was injured in August while crashing face-first into the cement wall in St. Louis. He then spent three years in active military service. Reiser injured his shoulder in the Army, and though he returned to the big leagues in 1946, he was never quite the same. He retired in 1952 after 10 big league seasons, having collected 786 hits and posting a career line of .295/.380/.450

Longoria, of course, is still writing the next chapter of his career, but he's off to a brilliant start. After being named the AL's top rookie in 2008, Longoria followed up with a tremdendous second season, hitting .281/.364/.526 with 33 homers and 113 RBIs, and an adjusted

OPS+ of 133. Though he suffered from injuries in 2011 and 2012, Longoria is still only 27 years old, and he remains one of the brightest stars in the league.

What does this tell us about Trout's future? Let's not pretend to read too much into this exercise, but it's an impressive list. Of the eight players who aren't currently active, six of them put together Hall of Fame careers. The other two -- Stirnweiss and Reiser -- have war-related reasons as to why they may not be good comparisons.

Trout and Longoria, then, appear to be in pretty good company. Trout also has 22 more games to catch Henderson. Should Trout remain healthy, there is every reason to believe he'll end up at the very top of the list.

So, yes, Trout has been historically great this season. What's more impressive is that last year Trout also had the best rookie season of any player in baseball history; in 2012, he hit .326/.399/.564 with 30 homers, leading the league in stolen bases and runs scored. Trout posted 10.9 wins above replacement, a number that no rookie has come particularly close to touching.

The kid just turned 22 years old. I can't wait to see what Trout has in store for us next season.