The Uniqueness of J.A. Happ

Pitchers without great fastballs tend to throw less of them. Old pitchers also tend to dial down their fastball usage as they age and throw pitches with more movement instead. The idea behind this is that deception is more valuable when a fastball loses its velocity, and pitches that move are better than pitches that are straight when velocity has declined. Do not tell this to J.A Happ, though, as the 38-year-old is throwing as many fastballs as ever.

Happ is 20th among 196 qualified pitchers in four-seam fastball percentage, with four-seamers making up 56.4% of his arsenal. Of the 19 players ahead of him, seven — Jacob DeGrom (33), Paolo Espino (34), Jake Odorizzi (31), Matt Moore (32), Andrew Heaney (30), Chad Green (30), and Brent Suter (31) — are over the age of 30.

Of this group, Green and Suter are relievers, while Espino has been used as a swingman and Moore has started just 10 of his 18 appearances. It is easier, and more common, for relievers to have a smaller and more concentrated arsenal, so these pitchers will be left out of the comparison. This leaves a group of just three full time starters — DeGrom, Odorizzi, and Heaney. DeGrom and Heaney both have elite spin rates (and velocity, in the case of DeGrom) on their four seamer, and Odorizzi plays for the Astros, so it makes sense that all three of them would throw so many four-seamers.

The interesting thing, is that Happ neither has elite spin rates, nor elite velocity, nor does he play for the Astros. In fact, his fastball velocity is in just the 15th percentile, while his fastball spin rate is in the 53rd percentile.

This is even more curious when secondary pitchers are examined. Of the 19 pitchers who throw a higher percentage of four-seamers than Happ, just five have thrown a sinker in 2021, with Suter throwing the highest percentage at 3.6%. Happ throws many more sinkers than these pitchers, with 14.4% of his arsenal made up of sinkers. When Happ’s sinkers are combined with his four-seamers, they account for 70.8% of his pitches. This is more than every qualified pitcher except for Brent Suter (73.2%).

For another comparison, let’s see how many fastballs are thrown by other pitchers of Happ’s age. This will exclude cutters, as, even though they are technically fastballs (cut-fastballs), some of them have more in common with sliders than fastballs. Beginning with the St. Louis Cardinals roster, Adam Wainwright throws 37.1% fastballs, Wade LeBlanc throws 38.9%, and Jon Lester throws 47.8%. Outside of St. Louis, 41-year-old Rich Hill throws fastballs 50.4% of the time. Even veteran relievers with smaller arsenals like Ervin Santana (46.8%), and Darren O’Day (51.3%) do not throw as many fastballs as Happ.

All of this is a long way of saying that Happ throws a lot of fastballs, especially for someone his age. This may be a unique strategy, but there is a clear idea with how the left-hander uses his pitches. He likes to throw his four-seamer up in the zone, but he will spread it throughout.

When he gets ahead in the count, though, it is clear what he likes to do with the pitch.

This is a pitch that Happ has struggled with on the year, as he has allowed a .391 wOBA and .363 xwOBA against the pitch. Much of this damage has been done from the 15 home runs that he has allowed with his four-seamer.

Throwing high fastballs can be risky when the fastball averages 91 mph and gets league average ‘rise’. This has certainly been true for Happ who has allowed most of his home runs on four-seam fastballs. MLB Film Room is a great place to check out the home runs that Happ has allowed on the pitch, and when all 15 home runs are examined, it is clear that most of the home runs he allowed were on fastballs that did not get high enough. There were at least five instances where his catcher called for a high fastball and the southpaw was unable to reach the top edge of the zone, and he paid for it.

When Happ misses below the top edge of the zone, his pitch lands squarely in the wheelhouse of plenty of hitters. His fastball is not good enough to consistently blow by hitters, so his strategy of pitching up in the zone with his four-seamer is risky because all it takes is one miss for a ball to end up in the seats. This is partially why Happ has the sixth highest home run rate (1.80 HR/9) among pitchers who have thrown at least 110 innings.

While Happ has surrendered 15 home runs on his four-seamer, he has yet to allow a long ball with his sinker. The southpaw’s sinker is an interesting pitch because it closely mirrors his changeup with drop and arm side run. The difference between the two pitches is that Happ’s sinker drops 0.9 inches less and runs 0.7 inches less while traveling 3.4 mph faster. Movement pattern is not the only thing these pitches have in common, though, as Happ locates them both in nearly identical spots.

Here is the location of his sinkers:

And here is the location of his changeups:

These pitches change the eye level of the hitter when paired with four-seamers up in the zone. That could be why these pitches have been more successful in 2021, as Happ’s sinker has allowed a .318 wOBA and his changeup has allowed a .317 wOBA. The xWOBA on these pitches are higher than their respective wOBAs, but these two pitches have allowed the lowest exit velocities of any of his offerings.

Although, Happ throws fastballs nearly 71% of the time, he does completely different things with his two fastball variations. As a result, they are able to be different enough for him to throw them with such high frequency despite having well below average velocity and average spin rates.

In his three games with the Cardinals, Happ has doubled down on his fastball dependency, throwing his four-seamer nearly 64% of the time and throwing his sinker nearly 11% of the time. This means that almost three quarters of the pitches that Happ has thrown in a Cardinals uniform have been fastballs.

While his sinker usage has been a bit down since arriving from Minnesota, it has increased every game, reaching 12% in his last outing. This could be a trend that continues, considering his modest success with the pitch as well as the fact that, unlike other organizations (Astros, Dodgers, Rays), the Cardinals still appreciate sinkers.

Another trend to watch will be Happ’s changeup usage as it has increased by almost 4% since joining the Cardinals. Considering the similar movement of this pitch to his sinker, it is also possible that Happ will throw more changeups and less sinkers in order to retain the movement pattern while dropping some velocity. It is difficult to come to any conclusions over a three game sample, but it is certainly something to watch as Happ continues to pitch for the Redbirds.

It is still early in his Cardinals career, but Happ has made an impact through his first three starts, and he has done so in a way that is uncharacteristic of many aging starting pitchers.