Tommy Pham has a changeup problem

Aside from Wednesday’s appearance from the #rallycat, few would disagree that Tommy Pham has been the highlight of an otherwise mediocre, at least until recently, Cardinals team in 2017. As John Fleming wrote yesterday, Pham has been not only the greatest surprise on this year’s Cardinals team, but also the biggest surprise in all of baseball.

Indeed, Pham has provided the Cardinals the same value Giancarlo Stanton has provided the Marlins. However, Pham has done it in 125 fewer plate appearances. To quantify things further, his average (.310) is good enough for 16th, his on-base percentage (.398) good enough for 10th, and his wRC+ (138) good enough for 21st (via Fangraphs). These are not National League rankings, which would still be impressive. This is how Pham stacks up against all professional players.

He is by no means a complete hitter. And that is just fine. You don’t have to be a complete hitter to be good. The only complete hitter in the game today is probably Mike Trout—the consensus best player in the game. Nevertheless, the Cardinals outfielder is having an extraordinary year at the plate.

One key to Pham’s 2017 breakout is his discipline. Not just his work ethic, his plate-discipline.

Fangraphs

Even in limited appearances in 2015 and 2016, Pham was better than the league average. And he has significantly improved this year as well. Still, for someone who rarely chases, his strikeout rate is slightly elevated (24.6%).

As expected, everything in baseball progresses in cycles. In it’s simplest form, a hitter makes an adjustment, so a pitcher makes an adjustment and so on. Pham’s K-rate is no different.

Fangraphs

This graphs shows his 15-game rolling K%. As you can see, there are stretches where he strikes out close to 30% of the time, but other phases where the rate dips below 20%. When I was combing through the data, I noticed an interesting link between Pham’s strikeout rate and the amount of changeups he sees. It isn’t a perfect correlation, but it’s interesting.

Fangraphs

I changed the rolling average from 15 games to 25 games to smooth out the data. It is perhaps an imperfect relationship, but it pointed toward an interesting trend. If you look closely, there are a few instances where an increase in changeup-percentage (CH%) indicates an increase in Pham’s K%. Around game 20, the CH% decreases and his K% drops shortly thereafter. Around game 50, the CH% increases and Pham’s K% followed suit.

According to Baseball Savant, in 2017 when he makes contact, Pham is hitting .367 against the offspeed pitch. However, he only puts the ball in play 18% of the time, only slightly higher than the rate at which he whiffs on the changeup—13%. That whiff% is the highest of any pitch he has seen more than 100 times (via BrooksBaseball).

Of course, at well under 300 pitches, we aren’t working with too terribly large of a sample size. So we can’t make any definitive statements. But it seems opposing pitchers have noticed something similar. As they throw Pham more and more off speed pitches—the number he sees continues to rise—he is whiffing more than on any other type of pitch.

BrooksBaseball

It’s a noticeable pattern, but not one that is significant on its own. However, I suspect that this is only one example of a league that is slowly learning how to attack Tommy Pham. His current level of production is not sustainable. The good news is, pitchers haven’t caught up to him just yet. Still, do we really think that a player who didn't start seeing everyday playing time until he was 30 is going to hit like this for even the next few years?

Pham has come a long way since beginning the year in AAA. He has earned his spot in the lineup and he’s also been the MVP of this team. That said, the first move the Cardinals front office should make this season is to trade him. Barring an epic collapse over the season’s final 50 games, his trade value will never be higher. And with the outfield prospects this organization has (3 of the organization’s top 6 prospects are OFers), his departure would leave no glaring hole.

What a package for Pham might include is something I’ll leave for another post. But selling high on a player who had a breakout season isn’t just the right move in this particular situation, it’s good business acumen, and it’s something the Cardinals front office ought to seriously consider.

As always, credit to BaseballSavant.com, Fangraphs.com, and BrooksBaseball.net for the data used in this post.