Has Harper reached his peak, or are better seasons ahead?

Bryce Harper, according to a large percentage of major-league players before the 2015 season, was the most overrated major-league player. Bryce Harper, according to 100 percent of the Most Valuable Player Award voters, was actually the most valuable player in the National League during the 2015 season.

So you can chalk that one up to … I don’t know. Something, though. Maybe this is why we still don’t pay any attention to the Players’ Choice Awards?

Maybe.

Either way, it’s hard to escape the conclusion that it’s now become almost impossible to overrate Bryce Harper, since he was pretty obviously the best player in the majors this year. At 22. Which leads me to Grant Brisbee’s recent column. Here’s the setup:

The question at hand, though, is this: Can Bryce Harper get even better? It’s a terrifying thought, but imagine a 22-year-old player winning the 2016 Rookie of the Year and you thinking, "Well, that’s as good as he’ll ever get." It wouldn’t happen. So we should at least look into the possibility that Harper will improve. And we’ll do it using baseball history.

Who were the players who a) finished with nine wins above replacement or more, and b) weren’t 23 yet? There were seven of them, and while WAR is a blunt object that factors in baserunning and defense, it’s still the best way to compare seasons across eras. Here are the players who were about as good as Harper at a similar age. Let’s see if they had even better seasons in store.

Actually, before we even get to Grant’s conclusion – OK, I’ll spoil it: Grant says history suggests that yes, Harper might well get even better. – I’m going to push back on a couple of things here.

One, I’m not at all sure that WAR is the best way to compare seasons across eras. I think it’s a great way to compare groups of seasons or (even better) groups of players across eras. But – and I say this while admitting I’ve done it many, many times – I’m not sure it’s the best way to compare a player’s single season in one era to another player’s single season in another era.

For one thing, in this case we’re talking about a terribly small sample size: only seven players (including Mike Trout twice). For another thing, the fielding component really gives me pause. Alex Rodriguez qualifies because of his 9.4 WAR when he was 20, but his dWAR – the fielding component of WAR – fluctuated wildly in his first six full seasons.

Now, this wouldn’t concern me if we were talking about a large group of players. But we’re talking about seven players. Which means if the dWAR is “wrong” for just two or three of them, our conclusions might be wildly different.

So I would rather leave defense out of the equation. And instead of looking at hitters 22 and younger, I prefer looking at a range of ages with Harper in the middle.

This still places Harper in an incredibly exclusive group.

There are only two seasons in this age range with a wOBA higher than .500 … and both of them are Ted Williams. Forget about Ted Williams. He’s just on a different planet.

Leaving aside Teddy Ballgame and Harper, there are 19 seasons in the .450-.500 range. But those were turned in by only 12 players, including Joe Jackson in all three years; and Jimmie Foxx, Ty Cobb, Eddie Mathews, and Ty Cobb twice apiece.

Remember, the question is about the likelihood of Harper improving.  His wOBA this season was .461, the 11th-best all time among players aged 21-23, and 44th best since World War II.

Let’s go through all 12 players. But quickly, friends!

Shoeless Joe Jackson posted his best wOBA at 21, his second-best at 22, and his third-best at 23. Then he fell off some – while of course remaining one of the American League’s best hitters – before jumping back to the top of the lists, or nearly to the top, at 29 and 30. But he never hit better than he had when he was 21.

Arky Vaughan’s best season came when he was 23. He was never so good again, and his four best seasons all came before he turned 27.

Ty Cobb makes the list at 22, improves at 23, and is slightly better at 24 and nearly as great at 25. Cobb aged exceptionally well … but you might still argue that his best four-season stretch came when he was 22-25 or 23-26.

Jimmie Foxx is on the list twice, with a .480 wOBA at 22, .458 at 23. But Foxx would enjoy many more huge seasons, including four with .500+ wOBAs. Those seasons weren’t a lot better than his Age-22 season, ranging from .507 to .522. Essentially, Foxx maintained a historic level of performance for around 12 years, showing no real decline until he was 33.

Joe DiMaggio makes the list at 22. He would have similarly great seasons at 24 and 26, but they were not better seasons.

Willie Mays posted a .471 wOBA at 23, which was really his first full season in the majors (he’d opened his Age 21 season in the minors, and spent most of his Age 22 season in the service). While he would obviously have other great seasons, many other great seasons, he never wOBA’d better than .450 again.

Next up is Stan Musial, but he’s a special case. For one thing, when he makes the list at 22 in 1943, many of the game’s best players are already in the military. Same thing in ’44 when he had basically the same season. Musial would basically have six or seven more seasons like those … except in context they’re significantly better, because by then most of the best players were not in the service (and you could argue that the league was also better because there were finally black players, but that’s got a negligible impact here because so few of those black players were pitchers). So while it might not look like it, just from the numbers alone, I suspect that Musial actually was significantly more talented, purely as a hitter, after those early seasons.

Albert Pujols’s first huge season (.461 wOBA) came in 2003, when he was 23. He would later have a few more seasons like that … but never one better.

Mel Ott’s story is basically the same, except he started younger: regular at 19, .475 wOBA at 20. Like Pujols, he would post some huge numbers in later seasons on his way to the Hall of Fame. But never as huge.

Al Simmons makes the list at 23 with a .455 wOBA, and he later posted three seasons in the .480-.484 range. Basically, from the ages of 23 to 29, his true ability seems to have been right around that .455, with natural fluctuations within around 30 points.

Eddie Mathews makes the list at both 21 and 22, with nearly identical wOBA’s (.451 and .452). He would never do quite so well again.

And finally we’ve got Mickey Mantle, who played regularly at 19 and became a star at 20. But he doesn’t make our list until his Age 23 season, in 1955. His greatest seasons came at 24 and 25, with a few more .400+ wOBA’s even later.

Looking at this list, I’ll allow that Foxx and Musial both improved some, or at least posted a few seasons that were demonstrably even better. Mantle, again, followed up his first great season immediately with two even greater. But that’s only three players in a dozen.

That said, you can look at this information and reach all sorts of conclusions, I’m sure. But what I’m seeing is that when you’re this good this young, you’re probably about as good as you’ll ever be. Which is plenty good enough? Everybody’s in the Hall of Fame except Jackson and Pujols, and that’s only because both are currently ineligible. Otherwise it would be 12 for 12, plus of course Ted Williams. So can we already assume that Harper’s going to finish with Hall-worthy numbers? Nah. What we know for sure is that he’s got Hall of Fame talent. For sure.

I am given pause by the surprising fact that Pujols and Harper are the only players on the list who debuted in the major leagues in the last 60 years; before them, you have to go all the way back to Mays and Mantle and Mathews in the early 1950s. So it’s possible that the old rules just shouldn’t be applied to modern players like Bryce Harper and Mike Trout.

Except there’s reason to think the opposite. A couple of years ago, Jeff Zimmerman published a study suggesting that players are actually peaking, or at least plateauing, earlier than we thought: “Once a hitter makes it to the majors, he doesn’t really improve. In the past, people used to hope for improvement and growth as the player aged. These days, people should expect to see the player performing at his career best immediately.”

I haven’t seen anything disproving Zimmerman’s conclusion, which itself disproved conclusions previously reached by Bill James (hitters peak around 27) and J.C. Bradbury (hitters peak around 29). But might they actually not peak at all, but instead begin their careers atop a plateau before beginning their slide downward around 26?

Different people get different answers, depending on their methodology.

But I recall having these same discussions about Mike Trout, and Trout’s wOBA’s have been essentially identical in his four full seasons. Based on 2,742 plate appearances, it seems that Trout arrived in the major leagues fully formed, as great with the bat as he would ever be.

Not that there’s anything wrong with that. I just think it’s unrealistic to think Bryce Harper can become even better. He’s been working toward this for most of his life, but at some point, a point that is perhaps earlier than almost everyone believes, all that work becomes merely maintenance rather than improvement.

Unless you’re Barry Bonds. Barry Bonds breaks everything. And I suppose we shouldn’t discount the possibility that Bryce Harper will figure out a way to break everything, too. But I won’t expect that until I see it. Nor should you.