The addition of Charlie Morton to Tampa’s rotation has really given them a competitive edge in the AL East. Morton signed with the Rays as a free agent after spending the 2018 season with Houston. While he’s always been a great pitcher, Morton’s skills have noticeably improved over the past few years, specifically after joining the Astros in 2017. So how did this happen? How did Morton go from an above average pitcher to one of the best in the league?
Increase in Strikeout Rate, Decrease in FIP and Hard Hit %
Morton’s strikeout rate increased from 2015 through 2019 and his hard hit percentage decreased. Hard hit percentage refers to the percent of balls hit with an exit velocity of 95 mph or greater. The lower the percentage is, the better for a pitcher.
His fielding independent pitching (FIP) also decreased over the past four seasons. FIP is more telling than ERA because it is not dependent on defense. The exception is in 2016, but Morton barely played that season due to an injury. Overall, his FIP is trending down.
The noticeable change in his numbers occurs when he starts with Houston in 2017. Because of his limited playing time in 2016, the majority of my analysis makes a comparison between the 2015 and 2017 seasons.
What Changed between 2015 and 2017?
The biggest change was Morton’s pitch mix. In 2015, he relied significantly more on his sinker. In 2017, he started utilizing his four seam fastball and curveball more. He used his four seam early on in his career but its usage faded over the years. It really wasn’t used much again until joining Houston. The increase in the use his curveball and the development of his four seam are what I consider to be the major difference makers for Morton.
| Pitch Type | Frequency 2015 | Frequency 2017 | Difference |
| Four Seam | 5.0% | 13.0% | 7.9% |
| Sinker | 62.6% | 41.3% | -21.3% |
| Curveball | 23.7% | 28.7% | 5.0% |
What’s so special about his curveball?
Morton’s curveball is an elite pitch. The horizontal movement on the curveball has always been significantly higher than MLB average, peaking at 8.5 inch above average in 2018. In 2019, Morton’s curveball had the 4th best horizontal movement in the league. The spin rate on his curveball is also top 7% in the league.
In all counts against left handed hitters, Morton increased his curveball use from 25% (2015) to 36% (2019). As a result, the opposing SLG decreased from .297 to .142.
How is Charlie Morton Increasing his Strikeout Rate?
In counts with two strikes, Morton used to rely primarily on his curveball and sinker. Starting in 2017, we see an increase in use of his curveball in counts with 2 strikes and a significant increase in the use of his four seam. His sinker usage significantly decreased (about 20%) against right and left handed hitters.
His four seam has above average horizontal movement. Between 2015 and 2017, Morton’s fastball had more than an 18% put away increase. Put away percentage refers to the rate of two strike pitches that result in a strikeout.
What made Charlie Morton develop his four seam fastball again after all those years?
The use of the two seam fastball (sinker) has been decreasing over the past decade. The data shows that opposing batters are more successful against two seam fastballs than four seam. The Astros were one of the first teams to pick this up, and developed their pitchers based on this information. Houston urges their pitchers to throw high, hard fastballs to get the strikeout.
Morton was appealing to the Astros because of the potential in developing his fastball, and the elite movement on his curveball. They were able to see that changes to his pitch mix (reducing the use of his sinker) would help turn him into an incredible pitcher.
Is Charlie Morton’s Sinker a Bad Pitch?
Absolutely Not. In fact, in 2019 Morton’s sinker had the third best horizontal movement in the league. However, the opposing SLG against his sinker increased from .446 to .504 in 2017. This is consistent with league wide data that suggests the sinker is an easier pitch to hit than the four seam.
Morton still uses his sinker successfully, as it follows a similar path as his curveball. See the overlay below comparing his sinker and curveball:
Morton Also Increased his Velocity
Between 2015 and 2019, the velocity on Charlie Morton’s sinker and four seam fastball increased about 4 mph. In 2015, Morton decided to start throwing harder (he was previously pitching for contact, which explains why his ground ball rate used to be higher than it is now). He changed his training and diet, lost 15 lbs, and gained strength and flexibility. As a result, he increased the velocity of his fastballs from 92 mph to 96 mph.
Concluding Thoughts
Between the velocity increase and varied pitch mix, Charlie Morton was able to go from a good pitcher to one of the top pitchers in the league. His pitches have great movement, are thrown hard, and used in a way that allows him to strikeout even the best hitters.