by Matthew de Marte – January 11th, 2018
Chicago Cubs president of baseball operations Theo Epstein has made a career out of making shrewd moves that provide outstanding value to his teams. Focusing solely on his time with the Cubs, Theo has done an excellent job of finding undervalued talent, or “diamonds in the rough.” This offseason, the Cubs have yet to make a major trade or sign any free agent to a deal worth more than $40 million. While many in baseball think the Cubs need to make a big move to bolster their pitching staff, such as signing Yu Darvish or re-signing Jake Arrieta, Theo’s reluctance to jump on the free agent market shows clear signs of confidence within the organization. Despite any headlining signings, the Cubs may have already made some outstanding moves. The Cubs have three excellent starting pitchers in Jon Lester, Kyle Hendricks and Jose Quintana, all of whom are under club control for a few more years. Swingman Mike Montgomery will also likely give the team another viable starting option.
The Cubs kicked off their offseason by signing former Rockie Tyler Chatwood to a 3 year, $38 million deal. There is nothing flashy about this signing when we look at Chatwood’s combined performance over the past two seasons:
Chatwood has had a below league average strikeout rate both seasons and a frightening 11.3 BB% and while his ERA+ (park-adjusted ERA) puts him at 15% better than league average over the past two seasons his 4.62 FIP negates the promise his ERA+ may provide. On the surface, the signing doesn’t look like it will bring a lot of value back to the Cubs. So what was Theo thinking? Chatwood’s home/road splits from 2017 may paint a better picture:
The metric I want to focus on is wOBA. wOBA, (or weighted on-base average), is a statistic based on linear weights, designed to measure a player’s overall offensive contributions per plate appearance. think of wOBA as a metric designed for a pitcher to evaluate how well hitters perform against him. At home, Chatwood’s .381 wOBA meant that the average hitter’s performance against him was equivalent to Cody Bellinger level production in 2017 (.380 wOBA). On the road, the average hitters performance was equivalent to Freddy Galvis in 2017 (.298 wOBA). Chatwood’s home-road splits are so dramatic, that average player performance against him varies from All-Star level production at home vs. well below league average on the road.
This performance gap can also be seen in his ERA, as there is a two and a half run difference between his home/road ERA. The most likely explanation for these splits is Chatwood has called Coors Field home his entire career. Coors Field has always been known as one of the best hitters ballparks in baseball. The fact that Chatwood is moving away from Coors could mean his .297 wOBA allowed on the road last year might be the best measure of the pitcher the Cubs signed. Looking at his pitch repertoire supports this idea as well. This graphic from baseball savant shows Chatwood’s velocity and spin rate for all of his pitches:
Last year, Chatwood had a fastball that averaged 94.84 MPH. Pair that with a spin rate averaging 2,480.4 RPM, well above league average MLB 4 seam fastball spin rate (2254.6 RPM), and we are looking at a player with a high potential ceiling. Despite his fastball ranking well above league average in terms of velocity and spin rate, hitters performed exceptionally well against his fastball. The table below shows how hitters performed against Chatwood’s 4 and 2 seam fastball.
|Pitch Type||# of pitches||BAA||SLG||HR||Whiff %|
For whatever reason, hitters have had no problem with Chatwood’s fastball. Even his whiff rate was below the league average of 10.5% on all pitches thrown. When looking at his Pitch f/x data, however, there may be an identifiable solution to this issue. The next two graphics will show the strike zone and Chatwood’s whiff%, and how hitters performed in each quadrant by batting average on 4 seam fastballs:
It is easy to see that Chatwood gets a ton of swings and misses up in the zone, and gets hit hard when his fastball is in the lower ⅔ of the zone. Perhaps more high fastballs would help Chatwood avoid the hard contact and help increase his strikeout rate. The next table shows the same information for his cutter and curveball featured in the table above for Chatwood’s fastball:
|Pitch type||# of pitches||BAA||SLG||HR||Whiff %|
Chatwood has tremendous offspeed pitches. This is supported not only by the high spin rates shown in the graphic from Statcast above, but in how poorly batters actually performed against them as well. Especially on Chatwood’s curveball his tremendous spin rate stands out.
To add to the argument that Chatwood should elevate his fastball more, one should consider the idea of pitch tunneling. Pitch tunneling is the idea that two different pitches (generally a fastball and an offspeed pitch) can be thrown from the same armslot and look nearly identical until the last second to hitters. High spin, elevated 4 seam fastballs and high spin 12-6 curveballs are a perfect pitch combination to use in describing effective pitch tunneling. The pitches play off each other and can look identical, giving pitchers a better chance of fooling hitters. The following tweet from Rob Friedman (@PitchingNinja) shows an example of Justin Verlander pitch tunneling.
Chatwood has the potential to be an incredible bargain for the Cubs and an excellent back-end starter for them over his three year contract. I don’t know what the ceiling for Chatwood could be, and I don’t want to place any specific numbers to what Chatwood’s 2018 season will look like, but I believe for the reasons stated above that his performance can be significantly elevated. Even if Chatwood becomes a 3-win pitcher, that is a vast improvement over the pitcher he was in Colorado, and would give the Cubs another reliable starter.
The Cubs could help Chatwood alter how he uses his repertoire the following ways: Increase the number of off speed pitches he throws, increase the usage of fastballs at the top of the zone and above the top of the zone. Look at the success pitchers like Rich Hill, Drew Pomeranz, or Trevor Bauer have had when changing how they use their arsenal to better pitch to their strengths. If Chatwood can make similar adjustments, it may result in huge dividends in his performance. Coupling his arsenal’s potential with Chatwood’s home/road splits, it becomes easy to see why Epstein may have found one of the best valued deals available on the free market.