Wei-Yin Chen and the Art of Changing Speeds

On Tuesday, Jon Paul Morosi of FOX Sports published a short column suggesting Wei-Yin Chen could be among the first free agent pitchers to sign. The column also included that agent Scott Boras is prepared to make the case that Chen is worth a higher AAV than what Rick Porcello earned last offseason, putting his yearly price tag north of $20 million.

When Morosi sent out a tweet that read “Is Wei-Yin Chen a $20 million-per-year pitcher? Or more? My column:” it was met with a frenzied response from The People of the Internet. Now, $20 million annually does seem a bit aggressive. But our crowdsourcing project pegged him for $13 million AAV, Dave Cameron thinks it will be closer to $16 million, and Cameron also named Chen as one of the five bargain buys of the offseason at that price. All it takes is a few teams to agree with Cameron’s assessment, and Chen’s price tag could be driven up near Boras’ demands.

The response to Morosi’s column shouldn’t be too surprising, for several reasons. For one, you should know that The People of the Internet are notoriously reactionary and easily agitated. Two, people almost always think players should earn less than what they actually end up making. And three, Wei-Yin Chen is probably better than most people think. He doesn’t blow people away, so he’s not a sexy pitcher, but he’s ran 3.44 ERA over the last couple years, and he’s done so in a hitter’s park in the AL East. His ERA- over that time is one point better than Chris Archer‘s, the same as Stephen Strasburg‘s, and one point worse than Madison Bumgarner’s.

I’m certainly not suggesting Chen is on, or even near, the level of an Archer, Strasburg, or Bumgarner, but he’s been about as durable as they come the last couple years with the results to boot. I’m not here to put a price tag on Wei-Yin Chen — I’ll let the market decide that — but Morosi’s column got me thinking about Chen, and thinking about Chen got me thinking about something else.

You’ll notice a couple paragraphs above that I only used ERA to evaluate Chen. Usually, we like to look at both ERA and FIP, and more information is always better, but Chen’s one of those tricky guys who seems to have proven himself as a FIP-beater, having outperformed his fielding independent numbers by nearly half a run since entering the league. Oftentimes, these FIP-beaters are guys who can consistently generate soft contact, and those kind of guys are among my favorite in baseball to think about right now.

On a related note, I explored how Dallas Keuchel goes about getting his soft contact last week. There’s plenty of ways to go about doing it, which makes it so fun to investigate. One of Keuchel’s methods is repeatedly pounding the first-base edge of the plate with two-seamers and changeups that tail away from the strike zone, hitting off the end of the bat against righties and jamming lefties.

That’s Keuchel’s method. Chen ranked sixth in the league in soft contact percentage this season, just three spots behind Keuchel. Chen’s got a method too.

Earlier this year, I was watching one of Chen’s starts, and something caught my attention. It’s simple enough, but it’s a starting point. Chen throws four pitches. Their average speeds are as follows:

  • Fastball: 92
  • Slider: 83
  • Changeup: 83
  • Curveball: 73

In a vacuum, none of those speeds seem out of the ordinary. As a whole, the arsenal is unique, in that there’s two instances of nearly 10 miles per hour in separation between speed brackets. There’s a pitch that goes 92, a pitch that goes 83 and breaks armside, a pitch that goes 83 and breaks gloveside, and a pitch that goes 20 mph slower than the fastest offering. That’s a lot for a hitter to deal with.

Sometime in the last year or so, I had a conversation with Indians pitching coach Mickey Callaway about Corey Kluber. Kluber, obviously, is one of the game’s best pitchers, but if there’s still a flaw to be found in his game it’s that sometimes teams can string together runs of hard contact against him. His career BABIP allowed is .317, and even in these last couple dominant years, his contact management hasn’t been elite. I prodded Callaway as to why this might be and he responded, quickly and confidently, that it’s mostly because Kluber relies on his fastball and cutter nearly 80% of the time, and those pitches average between 89-93 mph. Almost always, batters are ready for a hard pitch from Kluber, so when he isn’t locating well, it can be relatively easy to time him up.

With Chen’s arsenal, it’s tough to time him up. A hitter can never really sit on one speed, because if they’re sitting fast, they could see something 20 mph slower than they’re expecting. I wanted to see how unique Chen was in this regard, and what we might be able to learn about pitchers with similar arsenals.

What follows is a table showing qualified pitchers who most often changed speeds by more than 15 miles per hour in 2015:

Changing Speeds by >15 MPH
Pitcher Avg Change 15+ MPH Changes Total Pitches 15+ MPH Change%
Clayton Kershaw 19.5 708 3390 20.9%
Noah Syndergaard 16.9 390 2372 16.4%
Collin McHugh 17.4 474 3232 14.7%
Chris Tillman 16.6 370 2939 12.6%
Mike Fiers 17.2 371 3023 12.3%
Jon Lester 17.1 383 3184 12.0%
Scott Kazmir 16.9 345 2941 11.7%
Jered Weaver 16.9 270 2434 11.1%
Taijuan Walker 19.2 246 2620 9.4%
Chris Sale 17.0 295 3323 8.9%
Rick Porcello 17.3 240 2744 8.7%
Michael Wacha 18.4 255 2920 8.7%
Madison Bumgarner 16.4 265 3304 8.0%
Zack Greinke 18.2 257 3237 7.9%
Wei-Yin Chen 18.2 238 3010 7.9%
Trevor Bauer 16.5 218 2866 7.6%
Julio Teheran 19.0 233 3264 7.1%
Shelby Miller 16.6 220 3219 6.8%

Perhaps this table would be more instructive in analyzing Clayton Kershaw, because my goodness, but hey, there’s Wei-Yin Chen near the top of the league in drastic speed changes. And if you’re like me, something else stuck out about this table.

Present in the table is the king of low BABIPs and FIP-beating, Jered Weaver. Alongside Weaver is notorious FIP-beater Zack Greinke, and notorious FIP-beaters Julio Teheran and Shelby Miller, and longtime FIP-beater Chris Tillman, and recent FIP-beater Mike Fiers.

Naturally, this piqued my interest, so I ran some numbers with this group and found that the group, as a whole, posted a soft contact rate of 20%, where the league average is 18.5%, and a BABIP of .286, where the league average is .296. If single-year BABIP doesn’t strike your fancy, the group’s three-year BABIP is .284.

Certainly, this is far from any kind of rigorous study, and even then the results aren’t overwhelming, but the back of the envelope findings seem to support Callaway’s statements, and perhaps common logic, that pitchers who can drastically change speeds can keep hitters off balance, and keeping hitters off balance can help generate soft contact. Chen is one of those guys.

Before we wrap this up, let’s see some of these speed changes in action. I’d like to walk through an at-bat against Nelson Cruz from this August.

To start things off, Chen spots a 94 mph fastball on the outer half that Cruz takes for strike one. All Cruz has seen from Chen in this game, so far, is 94.

Chen comes back with a curveball, having shaved 19 mph off the previous pitch. It’s not a very good curveball, but it doesn’t get a swing, and in the sequence, it works.

After going 94 and 75 without a swing, Chen comes back with the heat, blowing Cruz away with a 94 mph fastball essentially right down the middle. This is the kind of pitch that Nelson Cruz crushes. And maybe Nelson Cruz would have crushed this pitch, if not for the most recent pitch he’d seen being nearly 20 mph slower.

Now with two strikes, Chen comes back with another fastball, elevated, trying to get Cruz to chase. Cruz took such a good cut at the last fastball, he was probably dying to see another just like it. Chen only gives Cruz half of what he wants, and Cruz doesn’t offer.

After going 94, 75, 95, 94, Chen comes back with the 75 one last time — this time, well-located — and Cruz is totally off balance. The end result is a weak fly out to right field.

Wei-Yin Chen isn’t overpowering, but he’s tricky. The upper and lower bounds of his arsenal’s velocity range 20 mph, and he changes speeds during at-bats with the best of them. The numbers seem to suggest that guys who change speeds like Chen have the ability to generate weak contact, a potentially underrated skill. Chen ranked sixth in the league in soft contact percentage last season and has proven himself as a FIP-beater since entering the league. Is he going to earn $13 million per year in free agency, $20 million, or somewhere in between? Can’t say! What I can say is that he’s a fun pitcher to think about, and at the very least, we learned something today.

Thanks to Jonah Pemstein and Jeff Zimmerman for research assistance

Author’s note: Shortly after publication, Nathaniel Rakich brought to my attention a FiveThirtyEight article by Rob Arthur from earlier in the year that found Chen was suppressing exit velocity more than any pitcher in baseball. You should read that too.





August used to cover the Indians for MLB and ohio.com, but now he's here and thinks writing these in the third person is weird. So you can reach me on Twitter @AugustFG_ or e-mail at august.fagerstrom@fangraphs.com.

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Mike Sonne
Member

Great work, August. We wrote about our “stuff” metric, which looked at peak velocity, change in velocity, and movement, and no matter how way we analyzed our data, Chen always seemed to show up at the top of the list.