The difference between Raúl Mondesí and Mookie Betts

Stop. Read the title of this article again. Now read it one more time. Okay, hopefully you read it as “the difference between Raúl Mondesí and Mookie Betts.” If so, you at least have a basic grasp of the English language. However reading is a two part thing. First, being able to read the words and know what those words means. The second part, something people often struggle with, is comprehension. Reading the words and understanding what the entire sentence means. You probably think you have step two down pretty well, and since you probably do, that title may have hurt your brain (this is all coming off really condescending). Raúl Mondesí wasn’t anything like Mookie Betts. You can prove it. Let me prove it for you:

I mean...Betts was worth 8.3 more wins than Mondesí last year, had 82 points more of OBP, and hit 133% better than him. “Those guys aren’t anything alike” you probably said in your mind when you read the title of the article (hopefully not out loud). Yeah, Betts was a lot better than Mondesí and “a lot” isn’t even a grand enough word to describe the difference between them.

So before you mutter to yourself “Shaun has lost all his proverbial marbles” and go back to browsing Facebook, let me show you one more thing:

I purposefully left out the axis titles and values here because I’m trying to build some suspense. Last year there were two data points that when put in a scatter plot as X and Y values bring Betts and Mondesí side by side like Castor and Pollux in the sky-like plot. They also aren’t two random variables like say OBP and batting average on a Tuesday. Instead, they are fairly strong descriptors of success for a hitter. Both variables are fairly new data points to look at as well. Okay, so the answer:

By launch angle and exit velocity, Mondesí and Betts were extremely close.

There are other interesting names on there as well. Mike Napoli is known for his prodigious pulled home runs for his career, Trea Turner finished behind Corey Seager for NL Rookie of the Year, and when Rougned Odor isn’t fighting Jose Bautista he’s hitting mammoth home runs. Mondesi had an exit velocity similar to all those guys (Kole Calhoun is no slouch either) but had nowhere near the results (Preston Tucker feels his pain).

Mondesí was miles worse as a hitter than the rest of his exit velocity peers. Exit velocity is always good. There is no such thing really as hitting the ball too hard. There is also though no “perfect” launch angle either. Here is a 99 MPH batted ball that just went as a long out from Mondesí and then a 95 MPH batted ball that went as a nice double:

The main difference between those two batted balls is four and a half degrees of positive angle. That may not sound like a lot but it’s about the difference between Mike Trout’s average launch angle and Alcides Escobar’s (and about 7 MPH of exit velo).

Looking a little deeper I wanted to see which batters are closest to Mondesí in both exit velocity and launch angle, and since I’m studying for the CFA exam (seriously don’t go look material up) I’ve had fun getting more into Z-Score (which I’ve used on this site before). Simply put Z-Score is the standard deviations above or below from a given point (usually the mean of the group). So a Z-Score of +/-1 means that value is one standard deviation above/below the mean. So using Mondesí’s EV and launch angle as the mean we can sum up the two respective value’s Z-Score’s to get a sort of similarity index:

Hey look! It’s a list of a bunch of at least 15% better than league average hitters and Jason Castro. Now all those guys accomplish their better than average hitting in different ways. Stephen Piscotty gets on base 36% of the time while Evan Gattis just beats the hell out of the ball. Either way, there are different ways to contribute at the plate and Mondesi shares a similarity to the above players in launch angle and exit velocity.

So would a slight adjustment upwards for Mondesí make sense? Possibly but we also have to remember the data we do have for both his EV and LA are collected from just 149 plate appearances. Exit velocity stabilizes pretty good at 50 batted balls while launch angle stabilizes a little early (this is after all based off mostly the hitter swing - something they’ve been doing the same for a decade). Mondesí put 62 balls in play last year so we just barely crossed the reliability threshold for the two metrics.

Generally the sweet spot for launch angle lies somewhere between 26-30 degrees and 98+ MPH (there is no ceiling here). Those types of batted balls go for extra base hits very often (many times home runs) and are hits 50% or more of the time.

A 90.5 MPH exit velocity average and 10.9 degree launch angle average is a decent one. In fact, that exact batted ball goes for a hit ~77% of the time:

Unfortunately 74% of those hits are singles with a rare double. That’s not bad I guess (a .767 average is pretty swell) but let’s see what a launch angle increase might do.

This is based on historical batted balls of course and Mondesí’s mileage may vary, but the sweet spot is somewhere between a 2-3 degree increase for him on (on average). Again that doesn’t seem like a lot but it is the difference between Mookie Betts and Mondesi batted ball wise.

Of course there are plenty of other differences between Betts and Mondesí too. If you are good at comprehension then you are probably saying “Shaun, you should have titled the article “one of the differences” between Raúl Mondesí and Mookie Betts” because there are many other differences between the two. The biggest perhaps is in their plate discipline profiles.

Betts swings at the ball 13.5% less of the time and when he does swing he makes contact 20.5% more of the time. He also swings outside the zone 18% less and when he does decide to swing at an outside pitch he makes contact with it 13% more of the time. For what it’s worth, Raúl Mondesí actually has inherently decent bat to ball skills. You may not notice it from his strikeout rate, but that’s just a function of swinging at pitches he has no reason to swing at. Stabbing for a ball in the dirt doesn’t often go well, but in the minor leagues he made contact at a league average rate or better. He’s also younger than my little brother so give him some time to come around perhaps, and you never know, he might hit like Mookie Betts. In a way... he already is.