The first pitch of an at-bat is often a pivotal moment that can define the encounter.
Certain players, such as José Altuve, are lauded for their “first-pitch aggressiveness.” In fact, in January 2018, MLB.com’s Matt Kelly published an article attributing part of Altuve’s 2017 AL MVP season to his aggressive approach at the plate. That year, he swung a league-high 279 times at the first pitch while sporting a healthy .449 batting average when those balls were put in play.
However, for less talented/polished players, that plate approach backfires.
I’d love to tell you the Miami Marlins recently acquired a player who embodies Altuve’s aggressiveness with his success. They certainly got one part of the equation. Jorge Alfaro: the man whose swings are so frequent, free, and loose it is almost like the baseball doesn’t even contact the bat because, well...it frequently doesn’t.
Typically when we analyze a batter’s “patience,” we look at his swing tendencies. A batter’s swing tendencies are the likelihoods that he will swing at certain pitches. As you would expect, a more “aggressive” batter tends to swing more frequently—both in general and on pitches outside the zone.
Labeling Alfaro as aggressive would seem like an understatement. He will swing at anything, and this can get him into trouble.
Alfaro is no stranger to the 0-1 count. In fact, of 27 catchers with more than 300 plate appearances in 2018, Alfaro suffered a first pitch strike third-most frequently (66.8% of the time). Why, you might ask? Just take a look for yourself at his zone profile:
Figure 1. Alfaro’s percentage of swings per first pitch across his zone profile in 2018
Alfaro swings at first pitches in various locations around the strike zone. What you may notice is there’s a lot of red outside the zone, too. Last season, pitchers liked to attack Alfaro below the strike zone, and why not? He swung at 34.7% of pitches in that location.
Of the pitches he swung at, the Phillies rookie frequently failed to make contact. Take a look at this next zone profile showing Alfaro’s whiffs per swing on first pitches—essentially the number of swings where he does not make contact.
Figure 2. Alfaro’s percentage of whiffs per first pitch swing across his zone profile in 2018
Not great. Not only did he miss 61.8% of the first pitches he swung at below the zone, but he also whiffed frequently elsewhere.
Digging deeper, we can do a little math to determine the probability of Alfaro swinging and missing at first pitches low and outside the strike zone. To determine the probability that a sequence of events will occur, you multiply the probabilities of each individual event (Alfaro’s swing probability times Alfaro’s whiff rate on these swings):
Pitchers facing Alfaro generated a swing and miss on 21.4% of first pitches below the zone. This means pitchers were able to generate a safe 0-1 count one in every five times that they either misfired or targeted beneath his knees. This isn’t even counting the pitches that he fouled off, etc.
This is so critical because Alfaro struggles when falling behind in the count. In 2018, Alfaro slashed .216/.254/.296 with a .244 wOBA when down 0-1 in the count, versus .308/.402/.538 with a .386 wOBA when up 1-0. So, for Alfaro, the first pitch is almost a make-or-break event.
Unfortunately, Alfaro’s problems don’t stop at the first pitch. His aggressiveness gets him in trouble throughout an at-bat, as he swings wildly and often whiffs.
Take a look at the chart below in which I rank Alfaro’s 2018 swing percentage (swing%), swing and miss percentage (miss%), swing percentage on pitches outside the zone (O-swing%), and swing and miss percentage on pitches outside the zone (O-miss%) versus 27 other catchers (min. 300 PA):
Table 1. Jorge Alfaro’s 2018 swing tendencies and league rank when compared to 27 other catchers who had a minimum of 300 plate appearances.
The numbers are disheartening. Not only did Alfaro swing the most of any other catcher with a minimum of 300 plate appearances in 2018, but he also had the most swings and misses. Even worse, he swung the second-most frequently at pitches outside the zone, and missed a staggering 57.10% of those swings—the most among all catchers included in this analysis. Oh, and did I mention he struck out in 36.6% of his at-bats in 2018? Yikes.
It’s a dramatic contrast in styles from old friend J.T. Realmuto. He ranked 14th, 18th, 17th and 17th in these categories, respectively.
So what does this all mean? Alfaro swings, and boy does he swing a lot. The problem is he also misses a lot. This poor plate discipline causes him to fall behind in the count frequently, a position in which he struggles.
Now what? We have to hope that Mike Pagliarulo and the Marlins hitting staff recognizes the 25-year-old’s wild swing tendencies, and works with him to improve plate discipline. The Marlins want “1-0 Alfaro,” the guy who slashes that beautiful .308/.402/.538 line and authors so many electrifying highlights. Please, leave a “0-1 Alfaro” back in Philly (or at least minimize his number of appearances).