MLB's playoff hopefuls that are poised to take advantage of the game's current trends

The playoffs can seem like a final exam offered to a lucky few who spent six months studying. We’ve seen league trends get pushed to the extreme in October. Things like higher velocity, increased breaking ball usage, bullpen games and openers have all been used when everything is on the line: Imagined in August, perfected in October.

Last year’s Fall Classic gave us some hints. Only two teams threw more cutters and sinkers than the Arizona Diamondbacks did in last year’s playoffs. Only one team threw more splitters than the Texas Rangers. Both teams likely benefit from some of the best hitting tech in baseball. They aced the test, and the rest of baseball should pay attention.

Then again, they’re only two teams, and all of baseball has been trying to solve the current riddle. Their different attempts to do so offer us some insight into what teams value right now. So let’s take a look at some league-wide trends have we seen over the past few years that might become relevant this postseason.

Multiple fastballs

Back when we were wondering where the offense went, one theme that emerged was that pitchers are making sure to vary the looks on their hardest pitches this season. The number of pitchers with three distinct fastballs has jumped by nearly 40 percent since 2021.

“Talking to hitting coaches, they’ll say our guys are struggling to prepare against guys with two fastballs, it’s important,” Detroit Tigers starter Casey Mize said recently of his decision to bring back the sinker he had mostly turfed since he was drafted.

Throwing three fastballs has a few different benefits. It means that the pitcher always has two fastballs he can switch between, no matter the handedness of the batter. Sinkers have big platoon splits, but four-seamers and cutters do not, so a pitcher doesn’t have to “give in” and throw the wrong type of fastball to the wrong hitter. This kind of thing can also confuse pitching models, which tend to pick a fastball as an “anchor” just as hitters tend to “sit fastball.” If you have multiple anchors, the model may have a hard time choosing where to start.

Here are the teams with the most pitchers who throw three fastballs:

Clearly the Philadelphia Phillies care about this, at least with their starters. Practically every starter in Philadelphia has added a fastball type, or ramped up the usage of one, over the past few years. Multiple fastball looks might have something to do with the Milwaukee Brewers’ success with pitchers like Tobias Myers and Colin Rea, as well as trade deadline acquisitions Frankie Montas and Aaron Civale. Atlanta Braves starter Max Fried has morphed from a pitcher that threw 58 percent four-seamers and very few other fastballs to one who now throws 33 percent four-seamers, 6 percent cutters and 16 percent sinkers.

But if the New York Mets make it, there may not be a better example of this phenomenon. Sean Manaea, Luis Severino, Tylor Megill, as well as a couple of relievers — they’ll be throwing all sorts of different fastballs to confuse hitters. That might be how they’ve overachieved their pitch modeling stats this season.

Practicing dirty

Slowly, teams are going away from batting practice that many call “eyewash” — useless work that makes the player look good — and favoring more difficult prep work. The Baltimore Orioles like “short box,” where the coach will come very close to the hitter and throw hard to mimic faster velocities from normal distances. When the Giants won the most games in San Francisco history, they had multiple machines and coaches on the field throwing from a few different distances. The new Trajekt pitching machine, which can mimic the action on most pitches and also has a hologram of the pitcher, is increasingly popular. Challenge the hitters before the game to make the game easier. “Practice dirty, play clean,” as Rangers offensive coordinator Donnie Ecker always puts it.

Figuring out who is benefiting from this type of preparation is nearly impossible. Ask a hitting coach, and most will say they do some version of that. Even figuring out who has a Trajekt machine is detective work. They have 40 out to professional teams, apparently, and 20 are in the majors.

“Just look at which teams have the biggest home/road splits, and you’ll see the Trajekt teams,” said one hitting coach who finds the advanced tech immensely important.

Well, here are the teams with the biggest home-field advantages this year, using wRC+, which is park-adjusted and should theoretically remove that effect from the difference.

The Diamondbacks have a Trajekt, and since Ecker is with the Rangers, it’s not a stretch to think they have one, too. The Los Angeles Dodgers are listed in the ESPN story as having one, too, so maybe there’s some truth to this. On the other hand, Rhys Hoskins says the Brewers have one, and they have been better on the road — just one of five teams that can say that this year. The Los Angeles Angels are also listed as having a Trajekt, and they’re practically the same offense home and away. The story also suggests that maybe the Diamondbacks don’t use their machine because of space limitations.

One thing this dependence on new technology does speak to, however, is the possibility that home-field advantages will change going forward. The Trajekt is not portable, and it’s likely that there are at least some offenses going into the playoffs that have benefited from that machine (or other non-portable training methods and technology) at home so far this year — and won’t have that available on the road.

Seam effects

Understanding some of the why behind the trends in pitch-mix usage around the league is important. Cutters and sinkers may be up this year because pitchers want more fastball types, but there might also be something else going on. Trends in pitch design may be changing pitch mixes, too.

Sliders are up, year over year, every year because they just do so well. The sport’s collective understanding of what makes a slider good is pretty advanced, and pretty much every team knows that velocity is good for sliders and that some basic shapes function better than others. But even then, as the league has become more advanced in understanding how the seams affect movement on the ball, we’ve seen a new slider proliferate through the league.

In other words: In early 2021, Barton Smith helped us understand the value of the wakes coming off the seams of the baseball as it flew through the air. By late 2021, we saw that the Dodgers were using seam-shifted wake to throw more sweepers than anyone. And now, we may be seeing secondary and tertiary effects of knowing the science behind the seams:

• The number of splitters has nearly doubled over the past five years.
• More sinkers will be thrown this season than last season for the first time in eight years.
• The number of sinker-throwers with plus-plus seam-shifted wake (as judged by axis deviation) is up 22 percent over 2022.

Which teams are most in on the seam-shifted wake sinker? Not the Dodgers or Tigers or Minnesota Twins — they’re in the bottom three of the league when it comes to sinkers with a big difference between spin-based and observed movement, AKA seam-shifted wake effects. No, it’s the Brewers (third-most, and almost 2,500 more than the Dodgers), New York Yankees (thanks mostly to Clay Holmes and Marcus Stroman), Diamondbacks (sixth) and Mets (seventh) that are benefitting from these newly scienced-up sinkers. The Seattle Mariners throw the third-most splitters in the league, so they’ve leveraged that science in different ways, perhaps.

Of course, these are season-long numbers, but there are still some standout players benefitting from seam-shifted wake who might make a huge difference this October. Blake Treinen, Andrés Munoz, Zack Wheeler, Brandon Pfaadt, Clarke Schmidt, Michael King and Fried all have sinkers that benefit from this effect. Mize, Jhoan Duran and Montas see this seam-shifted benefit on their splitters.

Watch the batter for funky looks this October, and you might be seeing the effect of the wake.

Rotation strength

Even if most research shows that the playoffs are mostly unpredictable, front offices are full of humans who will try to make sense of the chaos nonetheless. Remember back to the Kansas City Royals and Giants winning it all in 2014 and 2015. Neither had great starting rotations, and both were lauded for their bullpens. The league went to work on their pens. In 2014, pitchers averaged six innings (and 97 pitches) per start. Since then, we’ve seen those numbers drop by an entire inning and 12 pitches. Those are pitches going to bullpens now.

The changing nature of baseball is what makes trendspotting in the playoffs so difficult. If you take the average strength of the rotations of the World Series teams since 2014, you’ll find that they average out as the ninth-best in baseball and that the better rotation won five out of ten times. It would be fair to say that a decent rotation was good enough to go all the way. But those Giants and Royals rotations were in the bottom third of the league, and they may have changed the game. Take those two out, and the World Series winner has been the fifth-best rotation on average since, and the World Series loser the seventh-best. The better rotation won five out of eight times.

Ah-ha! So now it’s more important to have a better rotation because everyone has gotten the bullpen memo!

Here are the best playoff-contending rotations in baseball, judged only by the top four pitchers in the rotation, using their ppERA (ERA projected by using Stuff+ as well as traditional results) in neutral parks:

(Projections above courtesy of Jordan Rosenblum)

Well then, top of the list = contenders. Bottom of the list? Good luck.

Wait. Last year the eighth-best rotation beat the 15th-best. Sigh.

Two truths emerge from this kind of analysis, and they counter each other. One is that the playoffs are mostly random and that it’s probably folly to try and learn too much from any one tournament. The other is that every team will still try to do so, using the most recent trends in analysis and preparation. What else could they do but try to learn?

(Photo of Zack Wheeler: John Fisher / Getty Images)