It’s easy to consider over- and underachieving players in isolation. It’s only a little bit harder to put them in context. Below is some context. I exported a spreadsheet of every qualified position player on the season. Then I exported a spreadsheet of all our preseason projections, and I compared the two, looking at actual vs. projected WAR over however many trips to the plate each given player has had. Which players have underachieved expectations the most? Here are 10 names:

Prince Fielder is off his expected pace by about two and a half wins, which is absurd and terrible. Not that the Rangers have even really needed his help. But Fielder isn’t the only struggling star player, and right there in second is Andrew McCutchen, whom the Pirates could dearly use. He’s about tied with Giancarlo Stanton, who’s got his own problems, but let’s focus on one player at a time. McCutchen, by now, was supposed to be almost a three-win player. He hasn’t been close to a one-win player, and as he’s sunk, so has the team around him.

The Pirates have a whole lot of issues, sure. And the outfield as a whole has still been productive. Lower-budget teams, however, need their star players to be star players, and McCutchen hasn’t been a star player. It’s because he doesn’t have his swing.

This is a case where I don’t even need to speculate. Sometimes, we look at the numbers, and we figure there might be an underlying injury. With McCutchen, we know he’s had discomfort near his right thumb. It was somehow traced to a problem with his bat grip, and he’s trying not to grip the handle so tight, but these adjustments aren’t so easy to implement on the fly. You grip the bat how you grip the bat. You don’t want to have to think about something as fundamental as your grip, so this would be a process.

McCutchen’s WAR is down, and his WAR is down because his offense is down. He’s acknowledged that his right hand has hurt. How might these two points be connected? Here’s a little at-home experiment: Hold a baseball bat, or something vaguely resembling a baseball bat. Do you see how the bat is being held? It’s being held with your hands. That’s how the points are connected. Any kind of injury can be irritating, but the hands are the moneymakers.

McCutchen has said his swing has felt a little off since spring training. The numbers do show he wasn’t his normal self in April and May. But he was, at least, productive; June has been the stinker. Here’s everything, oversimplified:

Andrew McCutchen vs. Himself Split wRC+ BB% K% GB% Z-Sw – O-Sw% Hard-Hit% 2013 – 2015 157 13% 17% 40% 46% 40% April + May 116 10% 23% 30% 46% 35% June 39 7% 31% 40% 40% 28%

Earlier, you could’ve argued maybe McCutchen was trying to trade some contact for power. I remember considering that a few times, and while it wasn’t quite working out, it’s not like McCutchen was bad. He was just putting more balls in the air. That particular trend has reversed in June, but look at everything else. The walks are down more, the strikeouts are way up, and the contact is of inferior quality. McCutchen, earlier, was close to normal. It looks like only more recently has the right hand gotten the best of him.

This is a messy plot. It shows McCutchen’s big-league career, and rolling strikeout- and walk-rate averages.

You don’t want to see rates diverge like that. Not, at least, for a hitter. McCutchen has started to lose control of the zone, and he’s had issues with fastballs, and while he still fully remembers how to approach the plate like Andrew freaking McCutchen, right now he’s easier to exploit. Pitchers have less reason to be afraid of him, while he’s down, and he can do only so much to counter-attack when he’s physically compromised.

This is another rolling-average plot, made possible by Baseball Savant. It focuses on 2015 – 2016 exit velocity, but this one requires a little explanation. First, the rolling averages are based on 30-batted-ball samples. Next, I’ve included only liners, flies, and pop-ups, since McCutchen wants to be hitting his quality batted balls in the air. Finally, I’ve calculated rolling medians instead of rolling means, because it captures something about consistency. There are lots of ways to try to approach this data. This is only one of them. Anyway:

As with every stat, there’s some natural fluctuation. If you’ll remember, McCutchen started last year slowly, and that was because he had discomfort in his leg. That got better, and his swing got better, and you can see the improvement as April was quickly forgotten. The medians still bounced around, and McCutchen has a few relative troughs in there, but if you look all the way to the right, you see the latest dip. McCutchen hasn’t consistently hit the ball so hard lately. He had most of his strength earlier in the year, but lately it’s abandoned him. Maybe, from time to time, McCutchen takes swings that are pain-free. But it seems like there are enough painful swings that McCutchen hasn’t made his usual contact, either directly because of the pain, or indirectly due to attempts to compensate.

This is either encouraging or it’s not. Just last year, McCutchen played through injury, and he successfully returned to his old level of performance. This year’s injury, however, is a different one, and should it nag, it’s hard to see how McCutchen could get back to being himself. Maybe he really does just need to not grip the bat so hard, but for one thing, that could be a tricky adjustment, and for another, maybe that would sap some of his strength. Who’s to say? The best solution would be for the pain to go away, but with that, there are no guarantees. There are hopes, and there’s modern medicine, but hitters use their hands to swing countless times a day. The potential is there for the discomfort to drag on.

So for the second year in a row, Andrew McCutchen is trying to play at something well below 100%. Last time, it worked out, and the Pirates were better for it. Last time isn’t this time, but the Pirates, certainly, don’t need him any less.