Warren Whiffs on Fastball, Sizzles on Secondaries

During the offseason, Jason Heyward, John Lackey, and Ben Zobrist have dominated the discussion among fans and writers about the Cubs’ best moves. There isn’t much to dislike about any of the deals, really. Heyward and Lackey were the best position player and pitcher, respectively, on the St. Louis Cardinals. Getting both of them to the North Side is not only a huge boon for the Cubs’ roster but also leaves two huge holes on the Cardinals’ roster. Zobrist, for his part, is a favorite of manager Joe Maddon, a World Series champion with last year’s Royals, and by all accounts a great guy in the clubhouse.

In contrast, the least-celebrated major move of the offseason has been the trade that brought the Cubs pitcher Adam Warren from the Yankees. Remember him? When the Cubs pulled off the deal for Zobrist, they made a concurrent trade with New York designed to clear a space for the second baseman on the roster. That meant that Starlin Castro was going to play in black pinstripes next season instead of blue, and that Warren was coming to Chicago. With all of the angles involved in the roster shake-up, you can forgive anyone that didn’t take the time to look beyond the traditional numbers on the young pitcher.

Warren pitched in a swing-man role for the Yankees last season after pitching primarily in late-inning relief the year before. He’s a 28-year-old right-hander with a fastball that averages between 92 and 94 miles per hour, and has good stuff on his breaking pitches. Traditionally, his fastball has been his most-used pitch, followed closely by his slider as a secondary, the change-up as his tertiary pitch, and his curveball as his fourth pitch.

He also throws a sinker, but frankly it’s his worst and most infrequently used pitch. In 148 at-bats in his career, batters have hit .409 with a .641 slugging percentage and five home runs against the pitch—and it hasn’t improved much over time, as they hit .383 with a .517 slugging percentage in 60 at-bats against his sinker last year. It wouldn’t surprise me if Chris Bosio talked him into scrapping it altogether.

A few things have surprised me a bit about Warren when really diving into his peripheral stats. Let’s talk about them. Last season, for example, he had a 3.29 ERA, 3.56 FIP, and 3.43 DRA in 131 1/3 innings pitched. Those numbers are especially good for a guy that bounced between the rotation and the bullpen. But his K/9 was just 7.1, which is nothing to write home about—it places him 76th highest among all pitchers with at least 120 innings last year, in the same vicinity as Chris Heston, Ryan Vogelsong, and Jeff Locke.

In his 17 starts last year, that K/9 dropped down to just 6.3. While that’s extremely low for a starting pitcher—especially one that has such good stuff—it’s also a bit skewed by poor performance early in the season. But before I can explain that any further, more background is necessary to fully understand the importance of pitch usage to Warren.

Excluding the sinker, which we’ve determined to be dreadful, the fastball is pretty clearly Warren’s worst pitch. Six of the nine home runs Warren allowed in 2015 were hit off his fastball and, even with an extremely low .263 BABIP on the pitch, it came with the highest slugging percentage of his four main pitches. This is all pretty consistent with his career numbers, too. Despite being his most frequently thrown pitch, it’s the worst in batting average against, slugging, and ISO.

With all of that understood, take a look at the difference between the first six starts of the 2015 season for Warren, followed by his numbers of his next eight starts.


After starting out somewhat poorly, Warren settled down a bit and had a really nice stretch for the Yankees. With injuries to their rotation that sidelined Ivan Nova and Masahiro Tanaka early on, Warren was essentially the Yanks’ best starter in May and June. It wasn’t just luck, either. Warren made some changes after his early stretch saw him walk too many batters while not striking out nearly enough of them.

To wit, in his first six starts, Warren threw fastballs for 44.8 percent of his pitches while only throwing his slider 22.7 percent of the time and his change-up 15.3 percent of the time. Over the following eight starts, his fastball usage dropped down to just 29.8 percent while his slider bumped up to 28.7 percent and his change-up to 17.2 percent. These changes are probably responsible for the dramatic improvement of his overall numbers—especially the strikeout rate.

warren outcomes

Although none of his whiff percentages are particularly high, they’re definitely the highest on his change-up and slider. His fastball saw a whiff percentage of just 7.58 percent in 2015. For comparison, Kyle Hendricks’ mediocre 89 mph fastball generated a similar whiff percentage at 7.67. Sorry if that feels like I’m beating a dead horse, but it just doesn’t seem like a guy that can touch 95 on his fastball should be so ineffective with it.

But those secondary pitches, though! In 620 at-bats in Warren’s career against his slider, change-up, and curveball, hitters have put up just a .198 batting average with a .285 slugging percentage. To simply compare, batters have hit .299 and slugged .480 against his fastball and sinker in 448 at-bats. It’s not just that he’s getting more swings-and-misses on these pitches, too. The average exit velocity on his slider last year was 85.7 mph and 88.4 on his change-up, while his fastball hit 93.5 miles per hour on average. Even the balls in play, which with Warren will always be a part of the discussion, are hit with weaker contact on his three best pitches.

Warren has gotten by in his career to this point on the fact that he has three really good pitches, but he might be even better with fewer fastballs and sinkers and more of his “bread-and-butter” pitches. Or, by conjuring the same sort of magic he used on Jake Arrieta, maybe Bosio can figure out a way to help Warren be more effective with that low-to-mid-90s fastball.

Despite having spent the majority of his time in the major leagues in the bullpen and the Cubs’ 2016 rotation looking to be fairly set with Arrieta, Jon Lester, Lackey, Jason Hammel, and Hendricks, Warren is heading into the 2016 season preparing to be a starter:

“Obviously, I want to start. But I’ve pitched out the bullpen successfully as well. Again, this is a win-now mentality with this team so whatever we have to do to do that. They said they got me to be a starter, whether or not it’s this year, we’ll see. They’re giving me the opportunity to prove myself in spring training to be a starter, but I’m not unhappy being in the bullpen.”

With Bosio set to work with him in the spring, Warren could conceivably force his way into the starting rotation with some changes to his pitch usage or mechanics. If cutting down on the fastballs in favor of more of his secondary pitches is able to help him get more whiffs, fewer walks, and weaker contact on balls in play, Warren may develop into a high-end, middle-of-the-rotation pitcher. For a trade that’s known more for the player the Cubs gave up than the one the Cubs received in return, you have to love that potential.

Lead photo courtesy Anthony Gruppuso—USA Today Sports.

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6 comments on “Warren Whiffs on Fastball, Sizzles on Secondaries”


The Cubs actually need a bit of pitching upside. You can argue that Lester, Hammel, Hendricks and Lackey are going to stay about the same while likely some mild regression from Arrieta (let’s be fair here. He was amazing last year. Amazing is difficult to maintain regardless of who you are.) Overall that a very small net negative. Granted, the starting five that’s penciled in is still very good, but they need a solid option available if needed due to injury or ineffectiveness. Enter Warren. Nice article, thanks.


Great work, Vic; even anyone looking cursorily at old-school metrics (like a 3.66 ERA as a SP that was better than either Hammel’s or Hendricks’, and was right there with Lester’s after league adjustment; or a 2.29 ERA in the pen that was better than the marks put up by Strop, Motte, Richard, or Ramirez) could see Warren is a gem, and this was a steal. He also, in his life, has surrendered a lower OPS than any Cub starter except Arrieta (.651-.648), all while pitching in the offensive AL East.


CORRECTION: Warren’s life OPS is .685 (.648 in ’15). As such, Hendricks (.657) has him beat, but Warren beats Lester (.690), Lackey and Hammel.

Ryan Davis

Glad you liked it, and thanks for the comment. The Cubs definitely viewed more/better rotation depth as a priority in the offseason, and I think Warren accomplishes both. He’s a bright guy and a good personality, too. So I think he’ll work well with Bosio and maybe start to reach the potential of those filthy secondary pitches.


The fine writers here have already outlined how the Cubs’ horde of quality middle relievers may result in shorter starts this year. I’m curious if Warren may also be used as a spot starter to give Hammel and Hendricks, and maybe even Arrieta, a full extra day of rest here and there.

Given Hammel’s first half-second half splits, I also wonder if the Cubs envision using Warren in a flexible role in the first half with plans on weaving him into the rotation in the second half.

Ryan Davis

Rob, it wouldn’t surprise me at all if they planned to weave him into the rotation gradually.

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