Exploring Vladimir Guerrero jr.’s Batted Balls: Potential for Improvement

In parts 1 and 2 of this project, I looked at how Vladimir Guerrero strikes the ball, and how that compares to other MLB hitters. Now, to finish things off, I want to look at some optimistic futures. As I mentioned in part 1, hitters do the most damage on balls hit at over 95mph and at angles from 24 to 34 degrees. Guerrero hits plenty of balls hard enough, but mostly too low for maximum effect. In order to reach his potential, he’ll need to find ways to improve the proportion of balls he hits into play that are both hit hard and hit with the right amount of loft. In this piece, I’ll try to identify some hitters not unlike Guerrero who have done that, and see how it worked out for them.

To identify hitters who have succeeded in improving the quality of their contact, I identified all pairs of consecutive seasons between 2017 and 2020 in which a hitter put 100 balls in play in both. There were 773 season pairs that qualified. For each pair, I calculated the percentage of a hitters’ balls in play that were in the optimal contact range, then looked at the difference between the two. I decided that any increase of more than 2.5 percentage points, which was roughly the standard deviation of both the change between seasons and the difference across hitters within seasons, was large enough to qualify as meaningful. 120 season-pairs met that cutoff.

Those batters achieved their improvements in many different ways. Mookie Betts, for example, already had an above average launch angle in 2017, but had a massive breakout in 2018 by raising it a little more and by swinging way harder, adding about 4mph to his exit velocity. Travis Shaw bounced back from a disastrous 2019 to respectability in 2020 by actually lowering his launch angle by almost 5 degrees, turning an excessive number of pop-ups back into potentially dangerous fly balls. To focus in on hitters whose improvement started from a platform at least somewhat like Vlad’s, I used the same crossmatch test I explained in part 2 to identify the 10 pairs where the “before” season was most like Vlad’s 2020. These hitters, listed in the table below, should give some idea of what a quality of contact fueled breakout in 2021 might look like for him.

The average improvement in the rate of high quality contact among the group was 4.0 points. League average over the four year sample was a little under 6.6%, so these hitters mostly went from below average so significantly above. They already hit the ball harder than the league average of 88.1mph (which makes sense, otherwise they’d be odd matches for Guerrero), so the improvement there mostly takes the group from very good to near elite. League average launch angle for the four year period was 12.3 degrees, though, so even after the change half of the 10 comparators were still below the average there and only Odor moved into the top quarter of the league. Interestingly, on average the group didn’t really trade contact for power, with strikeout rates that were the same in both seasons. The story, then, seems to be that a group of sluggers who hit the ball hard but too low were able to hit it even harder and not quite as low, and that their overall performance got way better as a consequence.

Not every hitter’s changes appear the same, though. Perez actually decrease his launch angle and exit velocity between the two years, and Abreu and Desmond kept their launch angles essentially the same while adding more power. Those hitters really reinforce the point made in part 2 that the shape of distributions matter as much as averages, and that it’s possible to make more high quality contact with or without it showing up in those averages. To illustrate, let’s look a bit more closely at Jose Abreu and Marcell Ozuna, two of the best initial matches for Vlad and also the two hitters on the list who are closest to him in terms of their ability to make contact.

The image above compares Jose Abreu’s 2019 and 2020 distributions of batted balls. Essentially, what it looks like is that he stopped hitting both high flies and grounders below -10 degrees, both types of balls that almost never accomplish anything useful, focusing as many balls as possible in the narrow range where they’re most effective. It’s not hard to see how the overall average is relatively unchanged, but the shape of the distribution is a lot narrower and so more of it lies in the good ranges and less in the bad. Improvement along these lines for Guerrero would be similar to what I discussed when comparing him to Yelich in part 2. No major overhaul, but some tweaks to move a few balls on the margin from the good to bad regions. Abreu won the MVP for his efforts here, so this tighenting up approach can clearly pay major dividends.

Unlike Abreu, Ozuna does appear to have made wholesale changes that show up in the averages. He raised his launch angle by 2.9 degrees while adding 1.2mph of average exit velocity, both above average in the group. He probably hit a lower proportion of too-high fly balls in 2020, but he still hit a fair number. His ground balls below the 0 degree range have all but disappeared, though, even more dramatically than Abreu’s. He also really cut down on soft contact at all angles, with very few balls anywhere below about 80mph. Instead he’s maxed out on fly balls in the 30 degree bin at over 105mph, which are the best kind of contact a hitter can make. The overall effect is similar to what Abreu accomplished, but the way it was achieved looks a little bit more radical.

As we saw in part 2, Guerrero is a unique hitter, and even compared to this group of specially selected comparables he’s an outlier. He’s tied for the second lowest launch angle and has the hardest average exit velocity (in the “before” year) while striking out the least by a pretty big margin. As a result, he might not have as much room to increase his exit velocities (a 1.0mph increase would have put him fourth in baseball in 2020), but he might have more room to increase his launch angle. The upside is that, since he has more room to raise his launch angle and already hits more balls hard than most of them even without further growth in that area, he might expect an even bigger gain in overall performance than this group saw if he can make a launch angle change. The downside is that the change he’d need to make might be bigger than the comparatively minor tweaks some of the members of this group had to, and so might be harder to implement and maintain.

The finding about strikeouts also might not translate, because a bigger swing change might have a different impact on contact than a small one. Knapp, the biggest launch angle riser in the group and the one whose starting point on that scale was closest to Vlad’s, saw his strikeouts rise by 27% as a result of the changes he made. Even if that happened to Vlad, though, a similar relative change would only bring him up to 19.8%, which is still significantly better than league average. Unlike some members of this group, he has a lot of room to give in terms of strikeouts before it threatens his overall performance much, and if there’s a payoff in bigger damage on contact it could be very worth it.

Because of how extreme an outlier Guerrero is, I’d urge caution in drawing any strong conclusions from this group. His exit velocity, contact ability, and age speak to talent beyond even a group that contains two former MVPs, but he likely also has the furthest to go to maximize that talent. There are a couple of things I think can be said for sure, though. First, hitters who start from batted ball distributions somewhat like Guerrero’s can and do make changes that substantially improve their rates of high-quality contact. Beyond these 10, there were a dozen more who weren’t quite as close to start with but who still weren’t statistically significantly different and who made similar improvements. Second, on average the hitters who made those changes should be happy they did. 7 of the 10 comps in the table improved between the two seasons, and as a group they went from slightly below average to way above. Jose Abreu won the MVP as a result of these changes and Marcell Ozuna might have in a lot of years. Whether Guerrero can make a similar leap remains to be seen, but recent precedent shows that the possibility is on the table.