Expectations were high for the Boston Red Sox entering the 2015 season. After losing John Lester to free agency, Boston GM Ben Cherington brokered a trade for starting pitcher Rick Porcello. Cherington subsequently signed Porcello to a four-year, $82 million extension that, on an average annual basis, made him the highest-paid pitcher in the history of the organization.
Cherington's faith in his new pitcher went unrewarded, as Porcello had a disastrous first season with the Red Sox, going 9-15 with a 4.92 ERA (fourth-worst in the league among qualifying starters). He was a replacement-level player earning All-Star money.
Porcello wasn't the only failure in Boston that season: Despite being marked as a favorite to win the AL East, the Red Sox finished last in their division, and team ownership decided changes were needed. Cherington was ousted in August, in favor of Tigers' exec Dave Dombrowski.
Fortunes changed dramatically in 2016, with the Red Sox claiming the AL East title and Porcello claiming the AL Cy Young Award with a 22-4 record. While it could be expected that Porcello would improve upon his 'terrible' 2015 season, no one – with the possible exception of deposed GM Cherington—could have predicted such a dramatic turnaround. How then did Porcello go from bust-to-bargain, afterthought-to-ace?
Ricky Mears, founder of the Innings Pitched blog, explains below.
Let’s dive into the numbers and see how Rick Porcello went from league average to Cy Young in one year. I’ll spoil the punchline a little: The numbers may surprise you.
Peripherals of Pitching Arsenal
Porcello was known as a two-seam fastball, ground-ball pitcher with the Detroit Tigers.
Another major change from 2014 to 2015 was a nearly 7% increase in four-seam fastball usage. On the contrary, from 2015 to 2016, he lowered his four-seam fastball usage to 24.3%, well below his career average.
Two major takeaways here: Increased two-seam fastball usage and decreased four-seam fastball usage in 2016 compared to 2015.
Was the Increase in Two-Seam Fastball Really the Hero?
Rick Porcello, himself, cited a return to his roots for his 2016 success. He increased the use of his two-seam fastball and pounded the edges of the strike zone. He also minimized challenging hitters with his four-seam fastball. While the pitch breakdown reflects this change, the batting average against and slugging percentage paint a different pitcher:
While batting average against the two-seam and four-seam fastball decreased from 2015 to 2016, the real heroes are the changeup and the slider: The slugging percentage against the changeup and slider dropped nearly 200 points; batting average against his changeup dropped 163 points; it decreased 103 points against his slider.
When there are stark contrasts in numbers like this, we like to take a look at a few performance metrics. Velocity changes, heat-maps, and batting average on balls in play, to get the whole story.
Change in Pitching Velocities
So, what does this tell us? Rick Porcello was "over-pitching" in 2015, possibly trying to justify his contract extension. In the process, he diverted from his bread and butter, and tried to become a power pitcher. Over-pitching can lead to lost mechanics, missing location, and leaving pitches out over the middle of the plate.
Examining the Heatmaps
Rick Porcello struggled with spotting his changeup in 2015. He often missed high, or worse, he threw down the center of the plate (more than 20% of the time).
Comparatively, his 2016 changeup had a large spread, but generally remained in the bottom half of the strike-zone. A low changeup is a successful changeup.
Comparatively, the 2016 slider cluster is a thing of beauty. Neatly and tightly packed in the lower right corner (from the catcher’s perspective) of the zone. Hitters often were fooled, either striking out, or grounding out weakly.
Despite the major change in the execution of his changeup and slider, there is factor in Porcello's success:
Or in this case, bad luck on batting-average-on-balls-in-play (BABIP). Many fans overlook this metric. Simply stated, the pitcher has very little control on what happens after a ball is hit in play.
The league average on BABIP tends to hover around .300 each year. Porcello had extremely bad luck in 2015, when opponents generated a .332 BABIP. In 2016, Porcello’s BABIP dropped to .269, well below the approximate .300 league average.
As noted in the introduction, Porcello's 2015 season was a "disaster," and his 2016 season was fantastic. The two seasons appear to bear no resemblance to each other. But was Porcello really that much better in 2016, when he claimed the Cy Young award, as compared to 2015, when he was one of the "worst" pitchers in the league?
Fielding Independent Pitching (xFIP) assigns an ERA-like value to a pitcher's strikeout, home run, and walk rates in attempt to measure how successful a pitcher was at the things directly under his control. In other words, it strips defense from the equation. Factoring out defensive metrics reveals something striking about Porcello's two-year performance:
- 2015: 3.72 xFIP
- 2016: 3.89 xFIP
Now that Your Head is Spinning
Before chalking up his 2016 success to only defensive help and better spotting his changeup and slider, let’s take a look at Porcello's mechanics. Did tweaks to his pitching mechanics lead to success in 2016?
A normally telling sign is a pitchers release point and spin rate.
Examining the images below, we can see that his vertical and horizontal release points remain the same. The clusters do not vary drastically, vertically or horizontally.
Let’s take a look at his loading sequences, before you take our word for it.
This concept may sound advanced, but here is a simple exercise for you to consider. Make sure you have ample room before proceeding. Stand straight up and mimic throwing a baseball, probably seems pretty natural since you did not think too much about it. Remember that arm slot.
Now, lean forward at about a 45 degree angle, and pretend to throw a baseball. Likely, your arm slot changed to more side-arm or underhand action.
Last, repeat the same forward lean, and try your best to keep the arm path and release point the same. This is what Rick Porcello was doing. He leaned forward and in an effort to compensate the change, he bent his back leg. This allowed him to keep his arm in the same path (which felt natural to him), but also limited his uncoil (transfer of potential energy to kinetic energy) at the release point.
These subtle changes made his control slightly more erratic and affected his off-speed pitches such as the changeup or slider.
Wrapping up here, Rick Porcello turned the tide on 2016 due to the follow changes:
- Spotting his changeup
- Spotting his slider
- Reducing the velocity to minimize overthrowing
- Standing up straight in pitching mechanics, with his head over the center of gravity
- Substantially better defense that helped lower is BABIP below the league average.