*Stats and data included are current through June 5th.*
On May 22nd, Stephen Loftus of Fangraphs wrote about how Tommy Pham was continuing his breakout. Since then, the St. Louis Cardinals centerfielder has a wRC+ of 7. Seven. It’s the second worst slump of his career, surpassed in futility only by a 2016 stretch where he couldn’t see. It's the eighth worst mark in the Majors since that article. Tommy Pham is in a funk.
About a week ago, St. Louis manager, Mike Matheny, attributed Pham’s recent struggles to vision issues. Given Pham’s eyesight history, that comment was generally accepted without question. It’s likely part of the problem. However, there’s a new problem that’s popped up. The new problem isn't his eyesight.
First, a chart. The blue line is the percentage of pitches against Pham that were fastballs over his last fifteen games at any point this season. The red line is his wRC+ over the same fifteen game stretch (a 100 wRC+ is league average).
Pham is seeing more fastballs. That might seem like something, but Pham has mashed fastballs throughout his career. He’s slugged .556 against fourseamers, .440 against sinkers, and .769 against cutters (Pitch Info doesn’t classify cutters as fastballs here, but most people do). By itself, that doesn’t tell us much.
So, another chart. This one still shows his wRC+ over his last fifteen games in red, but now shows the average pitch height (Average Plate Z) against Pham over the same fifteen games in orange.
Pitchers are going upstairs on Pham more often. They’re throwing him fastballs more often. As a result, Pham is whiffing on fastballs more often, both as a percentage of total fastballs and as a percentage of fastball swings. The difference is telling.
When a pitcher throws a fastball, Pham is whiffing twice as often now as he was near the end of April and beginning of May. When Pham swings at a fastball, he’s whiffing twice as often. Prior to this slump, he had a career .409 wOBA against fastballs and a .441 wOBA this year. Since May 22nd, his wOBA against fastballs is .208. As recently as May 30th, he was striking out in nearly 40% of his plate appearances.
Based on those results, it looks like pitchers have found a hole in Pham’s swing. Using the heatmaps available on Fangraphs, we can see where that hole is exactly.
On the left is Pham’s career contact rate against pitches in each area of the strike zone from the pitcher’s perspective. Fastballs are on the right. He’s struggled to hit pitches high in the zone, especially high fastballs. He’s really struggled to handle pitches that are high and away. Pitchers have figured it out. Thanks to @cardinalsgifs, we can see exactly how it’s happening.
First up is a first inning strikeout against Ian Kennedy of the Royals from May 21st.
Kennedy misses his target here (by a lot) and leaves a fourseamer over the heart of the plate. It’s still pretty well located being at the very top edge of the zone, and Pham swings right under it for strike three.
Another way to visualize how a hitter struggles to square pitches up is to look at foul balls. Not all fouls are created equal, but a concentration of foul balls in one area might point to a weakness. Turns out, Pham hits a lot of foul balls in the same area where he’s more likely to whiff against fastballs.
That image is from the catcher's perspective, so the core is in the high-outside corner of the zone again. It further reinforces how Pham struggles to handle fastballs at the top of the zone. He often misses them completely, and he frequently just manages to foul them off.
Back to that game against the Royals. Later on in the sixth inning, he faced off with rookie Jason Adam. With a potential RBI sitting on second base and Pham in control of the count, Adam made a mistake fastball up over the plate. Pham just managed to foul it off, giving control of the plate appearance back to Adam. Adam would go on to fan Pham, ending the sixth inning and scoring threat.
Two days later, Kelvin Herrera of the Royals got Pham again on a high fastball. This time, the punch out came in the bottom of the tenth.
Pitchers started making changes in how they were attacking Pham in the second half of May. The Royals were at the front of that transition and may have helped other teams find his weakness.
About a week later, the Brewers and Pirates stole a page from the Royals to expose Tommy Pham. Here, Jacob Barnes goes high and hard twice to take Pham from a 2-0 hitters count back to even.
After taking the advantage, Barnes struck Pham out looking on the very next pitch.
Last one, this time coming courtesy of Trevor Williams and the Pirates.
Here, Pham fails to capitalize on a mistake fastball. That’s a pitch he should be able to drive. Instead, he hit a weak ground out on the next pitch.
Last year, Tommy Pham was the Cardinals best player and a surprise star. At 6.1 wins above replacement, he was worth nearly twice as much as the Cardinals second-best position player (Matt Carpenter at 3.1). He did it without seeing any MLB time in April. This year, he was doing it again for the first quarter of the season.
Since that quarter turn, Pham’s season has taken a turn for the worse as pitchers have found a way to attack him. The centerfielder’s negative 0.3 WAR over the last 14 days is the worst on the team in that span. Tommy Pham has overcome a mountain of adversity in his journey to stardom. It looks like he’ll have to overcome a little more on the field.
*Credit to Fangraphs, Baseball Savant, and Brooks Baseball for the data used in this post. In addition, a thank you to @ballparkbeef, whose discussion helped inspire and direct some of this research.