A few months ago, Ross Stripling appeared on the Effectively Wild podcast to discuss his approach to pitching. Stripling described a conversation he had with Dodgers general manager Andrew Friedman in 2016, after Stripling was sent down to the minors. That year, Stripling nearly pitched a no-hitter in his first start, but he soon began to struggle. He was sent down, and Friedman gave him instructions on what to work on in the minors. Stripling recalls:

When I got to the big leagues, I threw fastballs down in the zone. Everyone had always told me, ‘Throw down in the zone, down in the zone.’ Andrew [Friedman] comes up to me and basically says, ‘Hey, we’re gonna move you down, we got some stuff we want you to work on. We want you to throw up in the strike zone with your fastball.’ I’m just like, ‘I don’t know, man, I’ve always thrown down, you know, I think that’s what gives me success.’ But he showed me this thing with the average and [slugging percentage] against fastballs down in the zone and what they are up in the zone, and [the difference was] staggering, you know. Totally different.

Friedman had made similar adjustments with Jake Odorizzi during his time in Tampa Bay, and he asked Stripling to watch every Odorizzi start in the off-season. Stripling complied, and bought into Friedman’s program:

I spent a month in Arizona learning how to throw fastballs up in the zone and tunneling my curveball out of the same slot so they both start up in the zone. Obviously, my curveball falls down to either low in the zone or below in the zone. And basically from then on, I was throwing fastballs up and playing everything else off of that. That was a huge turning point in my career. For the most part, every big league hitter can hit down. Now, when I scout, I basically look at what zone—fastballs up and away, fastballs up and in, which one is the better hole.

Stripling isn’t exactly a star, but his change in approach has enabled him to craft a very successful career with the Dodgers. Stripling throws about 49.5% of his fastballs up in the zone. For the most part, he steers clear of the lower portion of the zone with his fastball:

Here’s what that looks like in practice:

The reasoning behind Stripling’s approach is simple. Pitchers have been told to locate their fastballs down in the zone for generations, but recently, hitters have learned to adapt. The launch angle revolution has resulted in uppercut swings that turn low fastballs into hard contact. As former Nationals pitching coach Derek Lilliquist summarized:

It’s a constant cat-and-mouse cycle of hitters adapting and pitchers adapting. In my era of pitching, there were [a] ton of [hitters] who handled fastballs at the belt and above. Those were the home runs in that era. You had to keep the ball on the knees. But now it’s shifting.

Or, as Rick Porcello told Buster Olney last year:

In this launch-angle era, Boston's Rick Porcello says that pitching in 2018 is about the barrel of the bat: You want to throw fastballs above the barrel, or breaking/offspeed stuff below the barrel. — Buster Olney (@Buster_ESPN) September 9, 2018

Organizationally, both the Astros and Dodgers (and others) have fully embraced the high fastball. Just last year, Astros pitching coach Brent Strom intimated that locating the fastball up was a large part of what helped the team remake both Charlie Morton and Gerritt Cole. The Dodgers, too, appear to be utilizing this approach. Hyun-jin Ryu targets the top of the zone with his fastball:

Rich Hill does too:

And so does sometimes-starter Julio Urias:

In fact, the only Dodgers starters who don’t shy away from the low fastball are Clayton Kershaw and Walker Buehler. Buehler, for instance, still trends up, but he throws his fastball down frequently as well:

We’ll talk about Buehler a little later.

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If you’ve been reading Purple Row this season (particularly this and this), it shouldn’t surprise you, but the Rockies don’t appear to have received the high-fastball memo. Jeff Bridich has publicly said that the team’s organizational philosophy involves locating the ball down in the zone. And a brief glance at the team’s heat maps reflects this, starting with Peter Lambert:

Then Antonio Senzatela:

Jon Gray:

And German Marquez:

Basically, the Rockies are going for this:

But often end up with this:

If the amorphous heat maps don’t convince you, just consider this: all Dodgers pitchers throw their fastballs above the belt at least 40% of the time. Two Dodgers pitchers (Hill and Urias) do so over 50% of the time, and Stripling is almost there too (49.5%). On the Rockies side, every pitcher besides Kyle Freeland and Jeff Hoffman is below the 40% threshold. At the back of the pack is Lambert, who only throws 31.6% of his fastballs above the belt.

Broadly speaking, there is a direct correlation between fastball-above-the-belt and fastball effectiveness. Here’s a table showing the Rockies and Dodgers starters by fastball usage, average fastball velocity, the percentage of fastballs above-the-belt, and fastball effectiveness. For fastball effectiveness, I’ve used expected weighted on base average, which is basically a measure of the quality of contact against a particular pitch.

Fastballs-Above-the-Belt and Fastball Effectiveness Pitcher Fastball Usage Average Fastball Velocity Fastball Above the Belt Fastball xwOBA Pitcher Fastball Usage Average Fastball Velocity Fastball Above the Belt Fastball xwOBA Dodgers Julio Urias 58.10% 95.1 56.90% 0.271 Rich Hill 46.30% 90.5 51.30% 0.265 Ross Stripling 35.10% 90.6 49.50% 0.332 Walker Buehler 53.30% 96.5 42.90% 0.277 Hyun-jin Ryu 28.40% 90.7 42.40% 0.284 Clayton Kershaw 46.50% 90.3 40.40% 0.327 Average 44.62% 92.3 47.23% 0.293 Rockies Jeff Hoffman 58.30% 93.8 48.00% 0.474 Kyle Freeland 41.60% 92 42.10% 0.393 Jon Gray 51.30% 96 37.80% 0.405 German Marquez 35.40% 95.7 36.30% 0.376 Antonio Senzatela 63.00% 93.8 35.20% 0.382 Peter Lambert 53.60% 92.6 31.60% 0.393 Average 50.53% 94.0 38.50% 0.404

The chart is pretty striking. The Dodgers do not throw harder than the Rockies. They do not throw as many fastballs as the Rockies. But they throw far more of their fastballs up in the zone, and on all fastballs—not just the ones up—they are far more effective. The average hitter is over a hundred points better in xwOBA against the Rockies than the Dodgers. Ross Stripling has the least effective Dodgers fastball, and it’s better than every single fastball thrown by a Rockies pitcher.

We said we’d talk about Walker Buehler a little later, so let’s talk about Walker Buehler.

Buehler’s approach is a little different because—to quote Mitchel Lichtman—if you throw hard, you can get away with a lot. Buehler throws with so much velocity that it doesn’t really matter if he locates his fastballs up in the zone. Hitters can’t catch up to his combination of velocity and movement regardless of location. He is still more effective up in the zone—a .238 wxOBA there versus a .296 wxOBA down in the zone—but the pitch is lethal regardless.

That also explains the success of Gray and Marquez this year. While both Gray and Marquez derive the lion’s share of their success from how their sliders play off their fastballs, both pitchers throw with so much velocity that it’s able to mask deeper problems with their approach. In other words, there’s no magic behind the fact that the only two successful Rockies starters this year are the ones who throw the hardest. All Rockies pitchers locate their fastball down in the zone. Only two throw hard enough to get away with it.

Of course, we should be cautious about advocating for a one-size-fits-all strategy. That’s bitten the Rockies in the past. Modern pitching doctrine urges pitching coaches to take a more individualized approach, and pitchers like like Kershaw and Freeland (well, 2018 Freeland) might have the location and movement to chart a different course. But for pitchers with a traditional fastball/breaking ball approach—especially those without premium velocity—the conclusion is clear.

Don’t do what pitchers have been doing for generations. Throw your fastball up.