When you think of a young hitter, you probably imagine a kid who can catch up to a fastball but struggles to lay off breaking balls and off-speed stuff outside the zone. There’s no “used to be a thrower but now he’s a pitcher” equivalent for hitters, but if there was it would likely be used to describe a batter who learned how to lay off tough sliders. When Yasiel Puig came up last year and couldn’t lay off sliders, and teams responded by throwing him sliders, it surprised nobody.

There’s some confirmation bias at work here. Try as we might not to, there’s a tendency to create cultural profiles for players, and also to create age profiles for players, and probably also to create behavioral profiles for players. So Puig—young, by appearances a bit out of control, Latin—seems to the prejudiced mind to be a guy who would be a free-swinger, and perhaps a guy who would swing and miss at sliders out of the zone. And he is, and he does! Just don’t throw that guy a fastball and you’ll be fine.

And yet, the surprise is that fastballs are actually, arguably, possibly, Puig’s relative weakness. Last year, when Puig swung at a fastball—which here includes four- and two-seamers and cutters—he whiffed 29 percent of the time. This is terribly high. Batters who took swings at Craig Kimbrel fastballs last year whiffed only 25 percent of the time. Thanks to Puig's near-impossible BABIP on grounders, his results on fastballs were credible, but his isolated power—.151—was low.

This is very odd for a young player. Since 2009, there have been 26 players who got 350 plate appearances or more in an age-22 season. Puig’s whiff/swing rate on fastballs was the worst of them; only Oswaldo Arcia (28 percent) and Mike Stanton (26 percent) were close, and only one other player (Jason Heyward) whiffed on more than a fifth of his fastball swings.

Now, Puig also whiffs more than most players on breaking balls and off-speed pitches. His whiff rate on fastballs was only 72 percent as high as his whiff rate on breaking and off-speed pitches. But that figure—72 percent—is way higher than the typical 22-year-old. Pablo Sandoval, amazingly, whiffed more often on fastballs than on breaking and off-speed pitches. But otherwise, since 2009, Puig stands alone:

22-Year-Old FB/Non-FB Whiff ratio
Sandoval 1.38
Puig 0.72
Hosmer 0.69
Beckham 0.69
Arcia 0.68
Rizzo 0.63
Stanton 0.58
Heyward 0.56
Myers 0.52
Tabata 0.52
Freeman 0.51
McCutchen 0.51
Parra 0.51
Franklin 0.49
Castro 0.49
Upton 0.49
Arenado 0.46
Lowrie 0.46
Andrus 0.43
Bruce 0.40
Rasmus 0.39
Cabrera 0.39
Montero 0.38
Altuve 0.32
Moustakas 0.32
Tejada 0.25

Puig is, in other words, not like the young hitter you imagine when you imagine a young hitter. Nick Franklin—that guy’s a 22-year-old hitter:

  • Fastballs: 21 percent whiff/swing
  • Breaking: 47 percent
  • Off-speed: 39 percent

Jesus Montero—that guy was a 22-year-old hitter:

  • Fastballs: 13 percent
  • Breaking: 34 percent
  • Off-speed: 34 percent

Justin Upton—that guy was a 22-year-old hitter:

  • Fastballs: 20 percent
  • Breaking: 37 percent
  • Off-speed: 45 percent

These feel like prototypical Young Hitter ratios, but as it turns out the "young" part of it seems to be a bad lead. Hitters don’t, it appears, change all that much with age. Our sample of 22-year-olds actually didn’t whiff any less often on breaking balls and off-speed pitches when they were 23. They did, however, whiff more often on fastballs than they had at 22—as a group and, in almost two-thirds of cases, individually. This isn’t close to an exhaustive sample, but if Puig follows his precedents, his troubles with fastballs could get even worse.

We tend to focus a lot on style. If we were pitching coaches or catchers, we’d have to. (And pitching coaches and catchers did; through July 22nd, Puig saw 57 percent fastballs, but from July 23rd on the league spiked that figure up to 62 percent.) But do we have to? Is there any reason to think that Puig’s particular style is significant? Should we conclude something important was happening in October, when postseason opponents threw Puig a whopping 65 percent fastballs—and he struck out 14 times and walked once in 41 plate appearances?

It’s tempting, from a narrative standpoint. Fastballs are the foundation of a pitcher’s plan. If establishing the fastball is so important for pitchers, why should it be any less important for Puig to establish that he can handle the fastball?

But we also know that good hitters come in all styles, and swing-and-miss is no disqualification to stardom. Chris Davis was one of the few players last year who whiffed nearly as often on fastballs as Puig. He survived.

In 2011 and 2012, there were a total of 45 hitters who whiffed on at least 25 percent of their fastball swings (minimum 200 swings) in either season. Seven didn’t get a significant amount of playing time the following season (one retired), and the remaining 38 underperformed their PECOTA-projected True Average the following season by about seven points. It’s a group that includes severe disappointments—B.J. Upton, J.P. Arencibia, Danny Espinosa—but also breakout stars: Brandon Moss, Chris Davis, along with the continued excellence of Giancarlo Stanton (who outperformed PECOTA each of the past two seasons).

So maybe it matters, maybe it doesn’t. All things considered, I’d take the guy who can hit fastballs instead of the guy who can’t. But, all things considered, it’s never possible to consider all things.

(Notable: In 2011, there were 20 players who whiffed on a quarter of their fastball swings. In 2012 there were 25. In 2013, thirty freaking eight.)

Thanks to Dan Brooks and Brooks Baseball for research assistance.