How much better will Harper be at 20?

How much better will Harper be at 20?
December 11, 2012, 8:45 am
Share This Post

Few 19-year-olds have ever done what Bryce Harper did for the Nationals this season, a fact that was repeated over and over during the course of his award-winning rookie campaign.

All along, there was an assumption that Harper had only scratched the surface of his immense abilities, and that he would be poised to take his game to even greater heights at age 20.

That assumption was based not only on Harper's individual case, but on the history of baseball itself, which features plenty of examples of young players making a significant leap once they turn 20.

How much better, though, can we expect Harper to be in 2013 than he was in 2012? By analyzing the career progressions of other prominent teenage ballplayers, we can start to get an idea.

There were 13 players in major-league history who received at least 400 plate appearances in their "age 19" season prior to Harper. That list includes Hall of Famers Mel Ott, Robin Yount and Al Kaline, likely future Hall of Famer Ken Griffey Jr. and teenage phenom Tony Conigliaro (who might well have made it to Cooperstown had his career not been derailed by injury).

It shouldn't come as a surprise that most of those players who saw significant time at 19 became better players at 20. How much better?

Well, there are some extreme cases. Like Ott, who after hitting 18 homers with 77 RBI as a 19-year-old clubbed 42 homers and drove in 151 runs the following season. Or Griffey, who raised his batting average from .264 at 19 to .300 at 20. Or Kaline, who made perhaps the greatest improvements between 19 and 20 by raising his home run total from four to 27, his RBI total from 43 to 102, his batting average from .276 to a league-leading .340 and his OPS from a paltry .652 to a stout .967.

It's not only those handful of big-name players who improved between age 19 and 20. On average, those 13 players raised their on-base percentage 11 points, their slugging percentage 19 points, their home run total 42 percent and their RBI total 27 percent.

That's a significant improvement when you consider the list includes a few 20-year-olds who regressed after strong performances as 19-year-olds.

What does this mean for Harper? Well, history suggests his home run total should rise 42 percent (from 22 to 31), his RBI total 27 percent (from 59 to 75), his on-base percentage 11 points (from .340 to .351) and his OPS 30 points (.817 to .847).

The Nationals would certainly take a 31-homer, .351-OBP, .847-OPS season out of Harper, though it probably goes without saying the young outfielder will be expecting even greater things out of himself.

Whether Harper actually exceeds those expectations and puts together a truly historic season at age 20 remains to be seen. There are all sorts of factors in play here, and there are no guarantees in baseball.

But the sport's history is a good place to start when trying to project future performance. And baseball history makes a compelling argument for a monster 2013 from Bryce Harper.