“What? Was? That?!?”

I had heard of Devin Williams before and knew he was a second round pick that had a knack for striking guys out. I even knew that he could throw 99mph heat and had the ability to generate weak contact with his offspeed stuff but I repeat…

“What? Was? That?!?”

Major League Pitches are not supposed to move like whiffle balls… especially changeups.

Watching Devin Williams this Spring gave me bottom of the ninth butterflies. The way he could command a pitch was immediately recognizable. The confidence he had while on the mound was palpable. Then he threw that changeup.

Even the boomers had never seen anything like it. Ever. The man invented a new pitch. A hypnotic blend of changeup, screwball and physics that melt opponents’ minds. Every time he threw it, he made another professional hitter look lost. The way they would smile on the way back to the dugout validated what we all knew…

There’s something special happening here. What it is ain’t exactly clear.

Mr. Williams had arrived and he announced it in spectacular fashion. A fire-breathing, glove-screaming reliever who knew how good he was (even if we didn’t yet). Since then, he has proceeded to pitch at a clip never seen before. We will dissect his season, closely examine the numbers and break down why he deserves all the awards. Devin Williams is in a League of his own and BREW MATHs can prove it.

A Rookie Year To Remember

Please take some time and familiarize yourself with the numbers on the chart (above). Once you realize that Williams led The MLB in ERA, FIP and xFIP it starts to become clear. This guy is elite. His ERA+ means that he is almost 14 times better than the average MLB Pitcher.

It is easy to get lost in all the fun next generation stats, but the raw numbers are just as impressive. Of the 100 professional hitters he faced, over half of them struck out. Moreover, of the eight hits Williams allowed, only two of them went for extra bases (a double and a homer; both off the fastball). His K% of 53.0 also led The MLB and was 44.0% higher than his BB%. In other words, for every guy Williams walks he strikes out almost six (5.89 K/BB). Devin struck out opponents at a clip of 17.67 K/9… the best mark in The League.

Williams was also one of two NL Relievers that had an fWAR above one. He finished the season with a mark of 1.4, while Rasiel Iglesias had a mark of 1.1.

Even When They Hit Him…

Things get crazier when you consider that even when opponents hit a pitch thrown by Williams, it goes nowhere… does nothing. In 2020, he threw 431 pitches which resulted in 37 batted ball events (foul balls count, too). That means a professional hitter only made contact with the ball eight percent of the time Williams threw a pitch (in the context of a 53.0 K%).

A closer look at what opposing hitters were able to do against Williams (i.e. not much):

MLB Percentiles

One look at Devin’s MLB Percentile Rankings drives it all home. He is basically the best at everything a pitcher can control. I will not waste a lot of words here since Baseball Savant beautifully highlights just how elite Williams is:

How Does Devin Do It?

The simple answer is that he makes hitters miss… a lot. He uses a 97mph laser dart (read: fastball with top-notch spin) to offset his 84mph changeup. Williams throws the changeup 52.7% of the time which makes sense when you consider the results. His fastball is thrown 41.8% of the time with cutters and sinkers making up the final 5.6%. This balance has proven to be unhittable.

Having 12.3mph between velocity bands forces hitters to stay on their toes… if they guess, they probably will miss. The fact that his average 4-seamer moves 52% more than comparable MLB Fastballs (+/- 2mph & +/- 0.5ft of release) makes it hard to hit. When you add in a changeup that moves 60% more than comparable MLB Fastballs, it becomes very difficult for opposing hitters to even make contact.

A quick look at his pitch-by-pitch results makes this clear.

Let’s not forget his accuracy, either. In order for all of this to work, he has to be able to command these pitches that defy physics. Easier said than done. Once again, Devin is up to the task and his heat map proves he is an artist.

As if this wasn’t all enough, Williams is ahead of the game and has already learned how to shape his changeup in different ways. Earlier this year, I asked him about that on Twitter and this was his response:

This interaction seems to validate two things:

1. Devin is approachable and a man of the people
2. He is a master of his craft who understands exactly what he is doing

Building upon that theme, we can take a closer look at his control through the eyes of the hitter. Opposing hitters’ plate discipline can shed light on what makes Devin so special. Comparing their numbers with MLB League Averages shows us Mr. Williams is not messing around…

Did I mention he is a 26-year-old rookie who is under team control until 2026?

Still Not Convinced?

Ok. Then let’s look at how Williams affects win probability… the ultimate test of a player’s value.

RE24: Context-dependent stat that assigns run expectancy value to each play. Despite the fact that this is a cumulative stat, only 19 starting pitchers ranked ahead of him. The two guys above him on the list? Cole and deGrom. The two guys below him on the list? Davies and Woodruff. Devin Williams is a reliever producing at the clip of an elite starter.

WPA: Similar to RE24 and represents the change in win expectancy from one plate appearance to the next. The Airbender is better than every other reliever in The National League.

cWPA: WPA is the number of percentage points that player increased or decreased their team’s probability of winning a single game. cWPA is the number of percentage points the player increased or decreased their team’s chances of winning The World Series.

Devin Williams increased his team’s chance of winning The World Series more than any other pitcher in The League. Let that sink in while you watch him bend air…

Suitable Comps?

When we compare Devin to other pitchers with a similar batted ball profile, these are the names that are on top of the list:

• Edwin Diaz
• James Karinchak
• Shane Bieber
• Trevor Rosenthal
• Corbin Burnes

Have you heard of any of these guys? The last name on the list should jump out at Brewers Fans. It is an homage to how The Brewers are able to develop pitchers in the lab. The fact that Williams got better as 2020 progressed seems to suggest his best is yet to come.

In Conclusion…

The Airbender has announced himself as one of the best pitchers on the planet. It is difficult to find any flaws in his game since he does everything at an elite level. Regardless of how you break him down, you’ll always come to the same conclusion…

Devin Williams deserves all the awards. Every one.