Mondesi's Amazing Turnaround

Everything was coming up Mondesi in September, but how much of that can carry over?

Ignoring the brevity of the 2020 season, it isn’t often that a player can be the worst hitter in the game for two-thirds of the season and then be one of the best for the rest. But Adalberto Mondesi did just that. If you’ve forgotten and think I’m exaggerating, the arbitrary endpoint of September 3rd tells the story. Mondesi hit .179/.209/.231 with a wRC+ of 14. The second worst wRC+ among qualified hitters in that span was 48. So he wasn’t just the worst. He was the worst BY FAR. 

Then from September 4th on, a switch flipped and he was literally a top five hitter in all of baseball with a .376/.424/.706 line, good for a 202 wRC+. That was the third best mark in all of baseball, behind Freddie Freeman, the NL MVP and Jose Ramirez, an AL MVP candidate. It really is one of those turnarounds you don’t see every season, even if you took 60 game chunks. It was just seemingly so sudden. What I wonder is if there’s any chance in the world that it sticks. 

This is the point where I tell you that I haven’t done any research yet to this point in my writing. I have no idea where this is going to go, but based on what I know from observing, I actually have an optimistic view on this. He’s not going to be the third best hitter in baseball in all likelihood, but I think that when I come to a conclusion at the end of all this that I’ll feel pretty good about Mondesi in 2021. It doesn’t hurt that he’s put some good swings on the ball in his limited spring training action so far. 

To the research!

The first thing I like to look at with any player is how they handled fastballs. For most guys, if they’re not hitting fastballs, they’re simply not hitting and that’s the truth with Mondesi. In his terrible start, Mondesi struggled with fastballs, hitting just .212 with a .288 slugging percentage and average exit velocity of 86.9 MPH. That was good for an xBA of .188. As he got hot, he hit .417 with an .813 SLG and 89.9 MPH average exit velocity. Now, the xBA on that last stretch of games was just .299, so he was in over his head a bit, but still, obviously better.

Without getting too granular and breaking it down by each side of the plate, I have a bit of a theory that pitchers started challenging Mondesi, and if you look at the heat maps, it does kind of add up. First is his brutal start followed by his scorching finish. 

Look at that center cut creamy goodness. So Mondesi got pitches to hit and he crushed them. Now let’s move on to offspeed stuff.

To start the year, he hit .219 with no extra base hits, but the xBA was .257. I’m not entirely sure why, given the average exit velocity on offspeed stuff was 77.7 MPH, but maybe it has to do with his speed and a slowly hit ball from him actually helps him out. Move forward and he hit .300 on offspeed stuff with an xBA of .200, but he did have six extra base hits. 

He did get challenged a little more on it, but if you look at the comparison here, it was a lot down in the zone and he didn’t really do much with it at all. 

There is a bit less being thrown outside the zone, so I think the overall conclusion sticks pretty well. 

Finally, let’s take a look at breaking balls before we move beyond this. 

He hit .083 with a .139 SLG and .121 xBA early in the year vs. .333 with a .630 SLG and .220 xBA when he was going well. I have to say that these xBA are not supporting my original hypothesis and they have me a bit worried. The heat maps for breaking balls don’t tell a huge story, but they don’t really fit the idea that he was being pitched less carefully, so I’m going to forego them now, but just know they’re not that interesting for what we’re discussing here today. 

Here’s a look at some of Mondesi’s plate discipline numbers with his frigid start compared to his scorching hot finish:

I find this chart fascinating, which might say more about me than anything. Obviously the walk rate is the big difference that people are going to key on, but I find the fact that he made less contact on bad pitches to maybe be a bit of a key to his success. Less contact leading to success might be counterintuitive, but think about the quality of contact on pitches outside the zone. Unless you’re Vladimir Guerrero, Sr. or another handful of players, swinging at those bad pitches isn’t going to lead to anything good, so actually missing may not be the worst thing. 

Here’s another chart because I love to give you things to look at with Mondesi’s numbers on pitches outside the strike zone compared to the league average. 

It shows that he found more success outside the strike zone when he stopped making so much contact. So he swung at fewer pitches than before and the ones he did swing at, he didn’t make contact as much. It actually does sort of make sense when you really think about it. 

That’s a lot of words and images without an answer, though, and you’re here for an answer of what we can expect from him in 2021. And the easy answer is if we look at what he did from September 4th on, it kind of seems like what he did from the right side is sustainable to some extent. He hit .444 (xBA of .335) with a 1.074 SLG (xSLG of .811) with an average exit velocity of 94 MPH and average distance of 194 feet on batted balls. That’s pretty impressive. 

The issue is that he only saw 29 percent of the pitches he saw in those final games from the right side. Even if you’re not a math major, you’ll know that he saw 71 percent from the left side, and the numbers weren’t quite so rosy. 

He hit .345 with a .534 SLG from the left side, which looks great on the surface, but the xBA was .228 and the xSLG was .361. His average exit velocity was 84.4 MPH and his average batted ball distance was 109 feet from the left side. That’s a huge difference. 

It’s not all bad. From the left side from September 4th on, he actually only chased 34.5 percent of pitches outside the zone, which was much better than what we saw from him from the right side. Are you seeing why he’s such a confusing player? As a righty, he chased 38.6 percent of bad pitches, but he was actually really good against them with a 95.5 MPH average exit velocity and average distance of 185 feet. 

I think it’s pretty obvious that Mondesi isn’t what he was at the end of the season, but the guy’s insane talent and natural ability can carry him for stretches. If the improved plate discipline is real and the ability to punish pitchers for throwing him strikes is real, then he has a chance to put together his best season yet. The issue is that we simply can’t count on the plate discipline from him. 

So what’s my conclusion here? I don’t think my hypothesis was right, but I’m not sure it was that wrong either. I feel good about him from the right side, but there are only four left-handed starters in the other four teams in the division according to the depth charts on Fangraphs. I like his chances to use his speed to pick up hits from the left side if he’s still taking pitches, but he’s also never really taken pitches before. 

So I guess my conclusion is that Mondesi is likely going to infuriate us for stretches and tantalize us as well. The Royals are banking on the tantalizing outweighing the frustrating and I think there’s at least a chance it actually happens this year. And if not, well, I’ll see you back here next here to determine if the six weeks he raked in 2021 could be what sets him up for a breakout in 2022.