The story of former Pittsburgh Pirates hurler Charlie Morton is a rather incredible one. Does his success foretell a change in the Bucs’ pitching philosophy?
Morton went from a solid back end of the rotation type pitcher during his time with the Pittsburgh Pirates and turned into one of the top 25 starting pitchers in the MLB, as ranked by Fangraphs’ WAR, this past season
In Morton’s own words, much of this turnaround was based on the Astros letting him pitch the way he wanted to, rather than having him pitch according to a certain strategy.
Charlie Morton in his transformation: pic.twitter.com/S21hB3ovrg
— Travis Sawchik (@Travis_Sawchik) October 29, 2017
This season, Morton went from “Ground Chuck”, known for pitching to contact, getting a lot of ground balls and posting a Strikeout per 9 innings of 6.75 with the Pittsburgh Pirates, into a dominant starter, posting a 10.0 K/9 with the Astros.
Many have cited Morton’s turn around as a criticism of the Pirates “pitch to contact” philosophy, arguing that if the Pirates simply left pitchers to pitch to their own strengths, the Pirates could be significantly better from the mound.
While nearly impossible to prove this directly, we can look at the impact of strikeouts on a number of different factors, such as runs allowed, types of contact, etc. to determine if there is any value in having a pitcher pitch to contact versus pitching for the strikeout.
We will start off with the end result and work our way backwards by looking at strikeouts per 9 versus ERA.
The red line denotes the trend line and each of the dots represent starting pitcher’s K/9 and ERA with at least 10 starts in 2017. The clear downwards sloping of the trend line tells us that with more strikeouts per 9 innings pitched we expect to see a lowering of a Pitcher’s ERA.
Setting aside Tyler Glasnow as an outlier, there are two groups of pitchers that the Pittsburgh Pirates have; in one group, Ivan Nova and Trevor Williams, and in the other, Chad Kuhl, Jameson Taillon and Gerrit Cole.
Nova and Williams seem to be thriving in the pitch to contact method, both having ERA’s a little less than 0.4 runs better than we would expect for a pitcher with their K/9 numbers. These are pitchers that should probably continue with this method.
Kuhl, Taillon and Cole on the other hand have ERA’s at roughly exactly what we would expect given their K/9. This suggests that these pitchers ought to be given more leeway and be encouraged to pitch for strikeouts more often.
This is in line with more traditional baseball thought. Nova and Williams aren’t “stuff guys” and aren’t going to dazzle opposing lineups, but rather are guys who can keep batters guessing and generating weak contact off the bat. Kuhl, Taillon and Cole, on the other hand, do have the impressive stuff and can generate swings and misses.
If just the three “stuff guys” increased their K/9 by 1 strikeout, it would have lowered each of their ERA’s by about 0.4 runs. That would give this group of starters an ERA of 3.99 versus their actual 4.22. That 3.99 ERA would have put the Pirates starting rotation as the 6th best in the MLB and 4th best in the NL versus their actual 12th and 7th rankings respectively.
A critique of pitching aggressively for strikeouts is that it can leave pitcher more vulnerable to contact; getting strikes means going into the strike zone, which in turn means leaving at least some pitches that batters can hit.
There are a few ways to look at this; the first is looking at how often balls in play go for hits relative to the strikeout rate, and the other is by looking at the quality of contact relative to the strikeout rate.
Looking again at starters with at least 10 starts and comparing their K/9 to their BABIP we get this:
The quick take away from this is the almost flat trend line; that means that there really isn’t any strong relationship between pitchers with higher strikeouts and pitchers with higher or lower BABIP (statistically speaking the p value of the slope is 0.837 which is nowhere near statistically significant). This really just means that high strikeout pitchers see no benefit or cost to the likelihood of a ball in play going for an out and the same goes for low strikeout pitchers.
Alternatively, if we look at the quality of contact using Average Exit Velocity of balls hit and Average Distance of balls hit against the pitcher’s K/9 we get:
Again, neither of these yield statistically significant correlations, meaning that a pitcher pitching for strikeouts or pitching for contact has effectively no impact on the contact made by the hitters (although not significant, strikeout’s impact on exit velocity does have a p value of 0.168 which is much better than the others).
When looking at strikeout rates in relation to home run rates, the effect is clear:
The negative correlation is telling, (and statistically significant, p=.0013) as throwing more strikeouts correlates to a lower home run rate.
What’s also telling about this data is that the home run problems that Cole and Nova had this year were pretty close to what we would expect from this data, based on how close they are to the trend line. While this doesn’t mean that both of them can’t work to lower their home run rates and beat the trend, it does mean that they have to put up better than average numbers, which is never an easy thing to do.
Some Final Notes
What all this means is that making all pitchers on your staff pitch to contact is rather silly, but it can be also be an effective tool for the right pitchers. In other words, it’s better to let stuff guys strike people out and let groundball guys let their fielders do the work.
Selecting these pitchers can be a bit tricky; Morton showed the ability to be a major leaguer as a groundball pitcher and it wasn’t until he was given the opportunity to be a strikeout guy that he really thrived. The flip side to Morton is the success that reclamation projects, like Francisco Liriano and A.J. Burnett, have had coming into a groundball system.
Allowing Cole, Taillon and Kuhl to explore pitching for strikeouts could, rather quickly, turn this staff from slightly above average into an elite. This is even truer for Tyler Glasnow; a pitcher who posted an astronomical 13.5 K/9 last season in the minors has no business letting bats anywhere near baseballs, let alone intentionally trying to generate weak contact.
Ultimately, this doesn’t mean that the Pirates should abandon the pitch to contact method all together, but rather, they should implement it with more discretion and allow pitchers who have the ability to strike guys out the opportunity to do so.