So…About This Sophomore Slump Thing: Is it Real and (How) Will it Affect the Cubs?

I distinctly remember the first time I heard the term “sophomore slump,” one of numerous plagues visited upon Cubs fans throughout time. My dad was worried that neither Jerome Walton nor Dwight Smith could repeat the magic of a season in which they’d finished 1-2 in the NL Rookie of the Year voting, though my 10-year-old optimism knew my old man was wrong. Well, until the 1990 season opened and I quickly saw that his fears were rooted in immutable fact. Or maybe just back luck. Either way, it was peak Cubbishness, not to mention an early entry in an ongoing series of events that forced me to admit my dad was right. Ugh.

Have you even seen a baseball player break out as a rookie, only to subsequently disappoint you with a follow-up season that closely resembled a used diaper filled with Indian food? If you answered “no,” you’ve probably only been following Major League Baseball for a year or so. If, however, you replied in the affirmative, you are likely familiar with the concept of the sophomore slump. As legend has it, an outstanding debut is reason for all kinds of fear because it means the player in question is that much more likely to regress. Think of it like a kid racing up a ladder and then jumping onto a slide to make his way back to earth.

The legend of the sophomore slump is based largely on the idea that some players are able to take advantage of a league that isn’t yet familiar with them. Once the book on a given player has been written and placed into circulation, the rest of the league can share it and mitigate those players’ strengths by exploiting their weaknesses. That makes sense on the surface, but it doesn’t hold quite as much water in today’s era of advanced scouting and in-depth metrics. Take Kris Bryant, for instance. You think opposing pitchers didn’t know anything about a guy who led college baseball in home runs and who absolutely torched his competition in the minors?

But since fear isn’t rational — and because drop-offs in performance are far from extinct — plenty of fans are still going to harbor anxiety about Bryant’s ability to live up to the hype that began as soon as the Cubs drafted him, culminating in one of the best rookie seasons in history. There’s also reason to worry about what is probably an unsustainably high BABIP and a frighteningly low contact rate. Oh, and then there’s the fact that Bryant is only one of four second-year players** in big roles for the Cubs. Repeated visits from the slump monster could yield disastrous results at Wrigley.

In an effort to discern both the veracity and/or the prevalence of the sophomore slump, I looked at the top rookie seasons by Cubs players in the last 30 years. Below are the 22 top seasons, along with those players’ second-year results (when applicable).

Okay, so that’s a lot of information to squeeze together. As such, I felt the need to unpack things a bit. Of the nearly two dozen players listed, only 8 saw a decrease in fWAR of one or more wins from their rookie campaign to the following season. Eleven players increased or maintained their fWAR totals, while Bryant, Addison Russell, and Kyle Schwarber have nothing to compare yet. Based only on those numbers alone, I’m tempted to dismiss the idea of the sophomore slump as little more than a convenient myth, but that might be a little hasty. After all, should the aforementioned trio all struggle in 2016, we’d be talking about an equal number of players on either side of the line.

But even if SchwarBrRussell improves as I expect them to, we’re still talking about a not-insignificant group of hitters that have fallen off dramatically. I suppose we could just chalk that up to some sort of karmic or metaphysical force acting against the hitters or their team, but that isn’t really fun. Well, it is actually kind of fun to just shrug and act as though the BABIP gods simply have it in for some guys. It’s not really accurate though, even if BABIP does factor in.

Check out the table below and see what I mean.

The eight hitters above posted an average BABIP* of .328 during their rookie seasons, then saw that average decrease by over 73 points, to .255, the following year. Given that .300 represents the general baseline for MLB’ers, we see that these characters went from very lucky to very unfortunate. As I’ve written in regard to Kris Bryant, though, there’s something to be said for a hitter’s ability to make his own luck. That’s where I turned to contact and batted-ball stats, which are admittedly limiting since they’re only available from the 2002 season on. Even so, there are some pretty clear trends in the guys whose numbers I could pull.

Geo Soto, Ty Colvin, and Junior Lake all saw significant decreases in both pull and hard-hit percentage, drops that could well explain some of the downward trends in BABIP. Since a harder-hit ball is more likely to drop safely, it’s easy to see how production could be eroded by a change in the way a player makes contact. As to why these players stopped pulling the ball, I’m going to have to make a bit of conjecture. Perhaps in an effort to make an impact upon being called up, a hitter employs more of a max-effort swing. And perhaps opposing pitchers are more willing to challenge the rookie inside. Over time, however, the hitter wants to round out his approach and he’s probably finding that he’s getting pitched around a little more as the result of his success.

A hitter who can adjust to changes both suggested and forced upon him is going to be better able to duplicate his early success. He’s also going to be more consistent, at least in a general sense. To wit, check out the stats from the guys who avoided slumps.

Anything jump out at you? I’m sure you’re already checking the BABIP differences and noticing how much less, well, noticeable they are. For instance, the average rookie BABIP in this sample was .310, a number that dropped to only .304 in the second year. That’s not only a sign of consistency, but also of sustainability. What’s more, these players’ rookie BABIP varied from their career averages by fewer than 19 points. If you take out Welington Castillo (40-point difference) and Darwin Barney (41), that average variation drops to just under 14 points. The variation in the slumping group: nearly 33 points.

You no doubt saw the highlighted numbers in the pull and hard-hit sections as well. You’ll recall that the three slumping players for whom we had data all saw marked decreases in both the percentages of balls they pulled and those they hit hard. Of the players who improved in their second season, only Barney’s pull percentage dropped and only he and Starlin Castro had less hard contact. Of course, both players made significantly more overall contact than anyone else on this list, thus whitewashing the decreases to an extent.

Is that it then? Guys who are more consistent are more likely to avoid slumping? Well, yeah, kinda. But there is more to it than that, and I’d like to poke around at it just a bit more here. Consider that the average rookie fWAR for the former group, the slumpers, was 2.19, while the latter group, we’ll call them the slump-busters in honor of Gracie, averaged only 1.39 fWAR. As for their careers, however, those respective groups averaged 5.65 and 11.5 fWAR. Of those impacted by a drop in year two, only Soto (13.3) and Davey Martinez (18.1) compiled more than 3.3 fWAR; only two (Damon Berryhill and Hee Seop Choi) in the second list finished with fewer than 4.5.

I suppose I could dig even deeper into this by checking the per-season averages just to make sure the increased numbers aren’t simply a matter of longer MLB tenures, but it’s not really necessary. While injuries and bad decisions have derailed many a career, poor performance is the ultimate arbiter. So, yes, the players in the latter group accrued higher WAR totals as the result of longer careers, but they had longer careers because they played better. It’s also possible that they were able to play better because they weren’t burdened by unrealistic expectations.

I’m not necessarily talking about the fans here, either, though that weighs into it. Think about it: Player X comes up and lights the world on fire, then spends the rest of his career trying to duplicate the success of that first season. For some players, that pressure may be too much to overcome. And maybe it’s not just him. You can imagine how a hitting coach or a manager might see all that potential and want to mold it into something even better. Maybe a given player’s luck simply ran out, or maybe he stopped making any of his own.

Whatever the case, those disappointing encore performances stick in fans’ minds more readily than do those campaigns in which a player simply maintains or makes minor improvements. The three highest rookie fWAR seasons of the 19 listed are found in the first group, largely because a better performance means there’s more room for regression moving forward. That may not be a very comforting thought as we head into 2016 with a team boasting the Cubs’ all-time best rookie fWAR season, not to mention two of the top three and three of the eight best debuts in the last 30 years. Knowing what we do from the numbers above, what can we project from Bryant, Russell, and Schwarber this season?

If we use the little indicators presented earlier, it would appear that Kris Bryant is primed for some serious regression. Insanely high BABIP: check. High fWAR total: check. High pull and hard-hit percentages: check and check. Then again, we’re not talking about a guy who suddenly burst onto the scene out of nowhere and who isn’t used to putting up monster numbers. Still, the potential is a little scary. I guess that goes both ways though, so I’d be lying if I said I was worried about him.

Is it unprofessional to assess the reigning ROY by saying that he’s simply so much more talented than the players listed above — all of them — that their outcomes really don’t apply to him? Perhaps. But that doesn’t mean it’s not the case. I’ll not retread the same ground over again but to say that Bryant is kind of like a planet unto himself, the kind of player whose gravitational pull forces others to conform to his game. He’s going to need to bring the contact numbers up significantly as he matures, but I think it’s safe to say he’s got the tools to be able to do it.

Schwarber’s numbers may scare you a little if you look to the far right to see that he led his compatriots in both pull and hard-hit percentage with numbers that more closely resemble those put up by the slumpers. On the other hand, his BABIP is appreciably lower than either Bryant or Russell and speaks to the fact that didn’t benefit from much, if any, luck in 2015. Like Bryant, Schwarber’s contact numbers are going to have to come up a bit, but, also like Bryant, I think he’s got the ability to improve them. When it comes to determining War Bear’s susceptibility to slump, though, I think we need to look a little beyond the numbers.

Earlier, I wrote that the concept at hand is as much a mental construct as anything else. Whether a given player just got hot or lucky, there’s a great deal of potential for him to come back to earth. How he deals with that regression says a lot about how good he can be moving forward. Hitting a baseball is probably the single hardest individual act in sports, but it’s far from simple physical exertion. You think a guy who’s got all kinds of noise in his head, whose confidence has been shaken by a few 0-for-5 performances, is going to have just as good a shot at squaring up that slider as the player whose mind is clear? No way.

Take a look at Schwarber’s batting average and wRC+ by month: June – .364/160; July – .302/151; August – .221/133; Sept/Oct – .208/111. That, my friends, is some serious drop-off. I have to point out, however, that it takes a pretty special hitter to perform 11% better than his average colleague while still only batting .208. Have you figured out where I’m going with this yet? You’ve got a rookie who closed the regular season on a 15-for-72 slide, a player who appeared to have serious potential to curl up into a ball when the pressure was ratcheted up ten-fold in the postseason.

Yet, all Schwarber did in the playoffs was slash .333/.419/.889 with 5 home runs and 8 RBI in 9 games. Oh, he also struck out only 8 times. You can’t take the small sample size of the playoffs and extrapolate it over an entire follow-up season, but the way this kid responded to his rookie struggles and absolutely showed out in October tells me a lot.

Finally, we have Addison Russell, he of the low(ish) wRC+ and relatively high BABIP. On the other hand, he displayed better overall contact rate than his teammates despite not hitting the ball as hard. He’ll never be a masher on par with Bryant and Schwarber, but Russell does have plenty of pop in his bat. As I wrote recently for another publication, I believe Russell will have a greater impact on the Cubs than the guy playing behind him in left.

He’ll have to make some adjustments, of course, but Russell’s ability to drive the ball to the gaps could make him an absolute terror. And while I’ve been focused on hitting for this exercise, the shortstop’s superior glove can’t be discounted. Not only will playing at his native position make him comfortable, but it should also keep him grounded and focused even if his offense slips at various points throughout the season.

So now that you’ve slogged through all that, I suppose I should get around to concluding this whole thing. When it comes to the idea of the sophomore slump, I’d have to say that it’s real. Well, inasmuch as peoples’ belief in it makes it so. Whether it’s the fans or the players themselves, fear of failure can sometimes be a self-fulfilling prophecy. There’s also the reality that a lot of the players who experience the dreaded sophomore slump were never really as good as their rookie numbers made them out to be.

And this, Cubs fans, is something in which you should find a great deal of solace. Call me a homer or a Pollyanna, but in Kris Bryant, Addison Russell, and Kyle Schwarber, I see three players who have yet to tap their full potential. If anything, I’d be willing to lean toward the possibility of a sophomore spurt for each of them. And there you have it.

Is there anything I missed in here? Any indicators for the success, or lack thereof, in Year Two that jumped out at you? Talk amongst yourselves.

*There’s some noise in these stats since I just took a straight average of the numbers and wasn’t willing or able to track down numbers on total balls in play for each hitter.

**You may be wondering why I didn’t include Jorge Soler in this list, though maybe you already know that his 0.1 fWAR left him unqualified. The prevailing opinion is that he’s primed for a huge breakout too, but you can’t really slump when you never really peaked.