April 28 is Mike Trout and Bryce Harper day

Mike Trout and Bryce Harper in their respective games on April 28, 2012 Getty Images

On April 28, 2012, two of the best players in baseball officially reached the major leagues for good.

Mike Trout, the American League MVP in 2014 and 2016, played in 40 games in 2011, but began the 2012 season with Triple-A Salt Lake. After hitting .403 in 20 games there to start the season, Trout was called up to the majors by the Los Angeles Angels for good on April 28. Trout went hitless that day and recorded just one hit in three April games, but picked up the pace in May, with 5 HR, 15 RBI and a .324 BA.

Bryce Harper, the 2015 National League MVP, debuted on this date in 2012 for the Washington Nationals at age 19. He went 1-for-3 with a double and an RBI at the Dodgers, in a Stephen Strasburg start. Harper is still just 24 years old.

The two went on to win Rookie of the Year honors in their respective leagues that season. Both got off to fast starts at young ages. They posted two of the four highest wins above replacement totals in a position player’s age-22 season or younger.

Each has won at least one MVP in addition to the Rookie of the Year honors, but there’s a clear difference in WAR total between the two. Trout has accumulated a total of 50.3 WAR in his career, while Harper is at 23.4.

Mike Trout

Trout’s 49.6 WAR since 2012 is the most in the majors in that span. The next-most WAR accumulated belongs to Clayton Kershaw (35.7).

Trout led the AL in WAR in each of the past five seasons. The last player to do that in either league was Babe Ruth, who did so in six straight seasons from 1926 to 1931.

Trout has finished top-2 in MVP voting in each of his five full seasons in the majors. The only other player to finish top-2 in MVP voting in five straight seasons, since the Baseball Writers' Association of America began voting on awards in 1931, was Barry Bonds in 2000 to 2004.

Bryce Harper

Harper’s journey hasn’t been as consistent as Trout’s. Harper won the 2012 Rookie of the Year award and the NL MVP in 2015 -- the youngest player to win MVP unanimously -- but then had a vastly different 2016.

With just 1.6 WAR in 2016, Harper posted the largest WAR drop off of any position player ever in his reigning MVP season, losing 8.3 WAR from his total in 2015.

Harper is off to a good start this season -- one that indicates he may be on track to have a season more like his 2015 performance than his 2016. Harper is leading the majors with a .418 batting average and is second with a 1.358 OPS.

But April wasn’t the issue last year, either. Harper hit nine HR in April last season and 15 the rest of the season, and that wasn’t the only rate that fell off. Harper hit .286 with an 1.121 OPS in April and followed it with a .235 batting average and a .759 OPS the rest of the season.