The Cubs have rescued Tyler Chatwood from Coors Field and much has already been made of his ground ball heavy mix, high spin-rate fastball and curveball and his line away from Coors Field the past two seasons:  157.1 IP, 7.0 K/9, 4.4 BB/9, 2.57 ERA and 4.23 FIP. The signing is being lauded as the steal of the off-season and a coup for the Cubs front office. If nothing else, the Cubs may have cut their cost per win for their John Lackey replacement from $8.5M per win from 2016-2017 ($32M; 3.7 WAR) to just over $4M per win from 2018-2020 ($38M; ~9 WAR).

What matters to the fantasy baseball community is how much can we trust these non-Coors Field numbers to represent Tyler Chatwood while pitching half his games at Wrigley and the other half in the same various other parks around (mostly) the National League? Our main goal will be to try and justify the hype that’s going to build around Chatwood throughout the winter leading up into draft and auction season. In order to understand that, we’ll have to dig into his numbers at a more detailed level to come up with some assessment of his skill to provide an updated projection for Chatwood in his new digs.

Let’s start with an assessment of Chatwood’s non-Coors skills.

 
We can quickly understand why FIP hates Tyler Chatwood. He loves to give up walks, but perhaps thanks in large part to his extreme ground ball profile he was among the best in baseball at limiting hits outside Coors Field. This is because ground balls turn into outs at very high rates. To put this in perspective, let’s look at all the starting pitchers with at least 100 innings pitched that recorded H/9 < 6.5 from 2015 to 2017.

 
That’s a very impressive list, but what’s interesting about this list of players is that they mostly did it with an average K/9 of 10.4+ while Chatwood checks in at a meager 7.2. Since much of Chatwood’s ability to beat his FIP on the road is tied up in his ability not to give up hits, we’ll want to understand if his .217 BABIP on the road is the product of his heavy groundball mix, or if it’s due to small sample size error over the 157.1 IP.

Let’s take a look at the correlation between GB% and BABIP to understand if this is a contributing factor to Chatwood’s road success or determine if we need to regress those road stats to get a more solid projection for 2018. Again, I looked at single-season BABIPs and GB% for every starting pitcher with at least 150IP.

Although there is a weak positive correlation with GB% on BABIP,  you can see Chatwood’s road stats over the past two seasons would be among the most prominent outliers in that group. Expanding the universe to cumulative innings pitched over the years 2015-2017 allows for starting pitcher BABIPs to stabilize as well as brings relief pitchers into the mix. When looking at Chatwood’s road stats through this lens we can now clearly see how much of an outlier his 2016-2017 road splits are. This leaves us just the task of assigning a projection, a tier, or a value to Chatwood’s 2018 or 2018-2020 tenure with the Cubs.

The list of pitchers with Chatwood’s road split skills:  < 7.5 K/9, > 4.0 BB/9 with a HR/FB% in the 12% range is very tiny. It includes Jimmy Nelson‘s disappointing 2016 season (0.7 WAR) and Tom Koehler‘s 2016 campaign (1.1 WAR). The limiting factor for success here appears to be the 4.0 BB/9. When I remove the K/9 restriction we find some other less than desirable fantasy arms, but there just aren’t that many starting pitchers working for Major League Baseball teams that walk more than four batters per nine innings. These high walk pitchers have averaged just 1.3 WAR with an average ERA north of 4.33 and WHIP above 1.40. The most successful pitching season in this group came from Mike Clevinger in 2017, but he logged 10.1 K/9 with a .273 BABIP over just 121.2 IP – some of that coming in relief.

In order for the Cubs and Chatwood’s fantasy owners to reap the rewards of pulling him out of Coors Field, he’ll have to make some changes to his pitch mix or tighten up his control overall. The ~2% increase in swinging strike rate from 2016 to 2017 was mostly supplied by a small improvement in the slider and a rather large second-half gain from the curveball after a slight horizontal release position change. If Chatwood can maintain that gain in swinging strike rate from the second half (11%), this would put him into a more rare class of pitchers even with his 3+ BB/9.

The curveball usage and corresponding swinging strike rate are the pair of metrics to keep an eye on from Chatwood in 2018. If he can maintain his gains, the comps become much more interesting:  Brad Peacock (2017), Mike Clevinger (2017), Danny Salazar (2016), Tyson Ross (2015) and Robbie Ray (2016). This is how the Cubs get their 3 WAR John Lackey replacement and how fantasy owners take a late-round flier and turn him into a useful asset. In his early 2018 rankings, Bobby Sylvester has Clevinger ranked #248, Brad Peacock #182, Danny Salazar #125 and Robbie Ray #57. My guess is that Chatwood will make an appearance in the Top 250 in the next version of these rankings.

Jim Melichar is a correspondent at FantasyPros. For more from Jim, check out his archive.