The Rays Way: Rising fastballs revisited

At the end of the 2014 season, Ken Rosenthal reported that the Rays instructed Drew Smyly to increase the number of high fastballs he throws in an effort to strike more hitters out. A few months later, Jeff Sullivan furthered this story, showing that the Rays have a history of acquiring pitchers with high vertical movement measurements on their fastballs as well as coaching their pitchers to throw their fastballs toward the top of the strike zone.

This organizational philosophy held true in 2015—the Rays' high fastball percentage (20.91%) was most in the league this season. The Orioles, who threw the second-most high fastballs, were a sizeable distance away at 19.04%.

There are clear benefits to throwing high fastballs. Work done by Jonah Pemstein at FanGraphs showed that batted ball rates change greatly with location in the strike zone, and the relationship between location and batted ball rate is strong. Pemstein's article suggests that throwing the ball higher in the zone causes more pop ups, which makes logical sense; the batter is more likely to make contact with the bottom half of the ball on a high pitch, sending it in the air. Because pop ups have a BABIP of essentially .000, they are almost "automatic outs" for a pitcher, and extremely beneficial.

Furthermore, throwing a high fastball increases its "effective velocity", which is the velocity perceived by the hitter. The idea behind effective velocity, which was developed by Perry Husband, is that the speed perceived by the hitter is greatly dependent on location of the pitch, and is based on response time and the arc of hitters' swings.

Pitches that are inside and high will seem faster to the hitter than the radar gun measures, and pitches low and away will seem slower than the radar gun speed. The following image, adapted from an article by SBNation's Jason Turbow, shows the impact locations of effective velocity. These strike zones are from the pitcher's perspective.

Basically, by throwing more fastballs up in the strike zone, Rays pitchers are making their fastballs seem like they are faster than the radar gun measures them. Husband's work suggests that increases from perceived velocity can be by as much as five miles per hour in the strike zone, and even more when pitching out of it. Faster perceived velocity leads to more whiffs, making Rays pitchers' fastballs more effective.

The increase in perceived velocity is complemented by the high vertical movement measurements that many of the Rays' fastballs' feature. While the association between fastball vertical movement and whiff rate is weak, Jeff Sullivan shows that fastballs with vertical movement measurements greater than one standard deviation above the mean tend to have the highest whiff rates. The explanation for this builds off the logic behind the concept of high fastballs increasing a pitcher's pop up rate on the pitch; the batter is swinging so far under the pitch that not only is he not making solid contact, he misses altogether.

2015 High Fastball Rates

While this seems to be an effective team strategy, each pitcher's implementation of it varies. Looking at high fastball rates for Rays pitchers will show who has implemented it the most, but looking at changes in high fastball rate from last season to this season will help show trends in usage as well.

I classified high fastballs using Baseball Savant, and set the zones of high fastballs as 1, 2, 3, 11 and 12 on the Baseball Savant zone breakdown.

Player	2014 High Fastball Percentage	2015 High Fastball Percentage	Δ High Fastball Percentage
Jake Odorizzi	61.61%	57.85%	-3.76%
Chris Archer	47.50%	52.13%	4.63%
Brandon Gomes	34.69%	49.72%	15.02%
Steve Geltz	55.45%	45.11%	-10.34%
Drew Smyly	45.78%	44.17%	-1.60%
Jake McGee	47.46%	42.30%	-5.16%
Nathan Karns	34.81%	41.16%	6.34%
Alex Colome	46.93%	39.79%	-7.14%
Brad Boxberger	44.38%	38.42%	-5.97%
Kirby Yates	32.60%	37.90%	5.30%
Erasmo Ramirez	42.81%	37.01%	-5.80%
Xavier Cedeno	33.78%	30.72%	-3.06%

Using a "bucket" method and grouping pitches into absolutes ("high" or not) isn't a perfect method, because a pitcher could have a large percentage of pitches that just miss the height threshold to be counted as a high fastball. As a result of this, these percentages aren't extremely precise, but we can still look at the general rates and changes to draw meaningful conclusions.

This season, the league average high fastball rate was 41.9% (high fastballs/total fastballs). Half of the qualifying Rays pitchers had high fastball rates above league average, and Nathan Karns was just a few pitches below the league average. This shows that high fastballs are implemented by the majority of pitchers on the team, and it isn't just a few extreme cases that are driving up the team average.

Erasmo Ramirez and Xavier Cedeno, who had the two lowest high fastball rates on the team this year, were both new to the Rays this season, which provides a possible explanation for the low elevated fastball rate, as it may take time to change a player's approach.

Jake Odorizzi doesn't have blistering fastball velocity at 92.3 mph, but he has still posted a historically above league average whiff rate on the pitch. In 2015, he recorded a 21.86% whiff rate, which is well above the league average of 16.4%. Much of the credit for the high whiff rate comes from throwing it high and having a a lot of vertical movement on his fastball. He is among the leaders in high fastball percentage around the league, with 57.85% of his fastballs fitting the criteria, making his fastball velocity seem much greater than the data says. Odorizzi also has the most fastball vertical movement in the league according to FanGraphs, which helps his fastballs sit above hitters' bats and cause them to whiff. Odorizzi is clearly taking advantage of the increase in perceived velocity at the top of the strike zone, and it has been a large part of his success.

Unsuccessful High Fastballs

Brandon Gomes had the largest increase in high fastball rate this season, and clearly stands out on the graph. Theoretically, throwing more high fastballs should have made him a more effective pitcher, but the results are again uninspiring from Gomes. He has posted a 4.27 ERA this season with a 4.76 FIP, which is likely driven from a 1.53 HR/9. He has an extreme fly ball rate (48.9% of balls in play), so the high home run total is partially expected, because pitchers have little control over how far opposing hitter's fly balls travel.

By throwing more high fastballs, Gomes would theoretically increase his fly ball percentage and become an even more extreme fly ball pitcher. Like pop ups, expected fly ball rate increases as pitches are higher in the strike zone. However, the fly ball rate on his fastball actually decreased, moving from 32.35% to 29.41%.

Looking at heat maps of Gomes' fastball usage helps explain the lack of an increase in fly balls on his fastball. Below is a heat map of his fastball usage against lefties, whom he primarily uses his fastball against, and the subsequent swing rate heat map of those pitches.

While Gomes is throwing more fastballs up and out of the strike zone, lefties aren't chasing them, obviously mitigating the effect of the high fastball; they can't fly out, pop out or whiff if they aren't swinging at it. Gomes' lack of improvement seems to suggest that there is a limit to how high these fastballs can be for them to be an "effective high fastball". It appears that Gomes is either throwing these fastballs too high, or is missing another unknown element, like height, a piece of his pitch arsenal, or deception, needed for the high fastball to be truly effective.

But, he did see more whiffs with his breaking pitches. Alternating high fastballs and breaking pitches thrown lower in the zone would force the hitter to not only adjust for the change in speed, which is magnified by the increased perceived velocity, but the change in eye level as well. The following images demonstrate changing eye levels.

The image on the top shows a side view of the path of Gomes' fastball in 2015, and the image on the bottom shows the path of his slider. These two pitches have distinctly different trajectories, and when released from the same original height, have a difference in final height of nearly two feet. Furthermore, the pitches in the images above are originally aimed for the same spot; if the fastball target was elevated in the images, the difference between the two pitches would be even more pronounced. Changing eye levels like this keeps hitters off balance, and seems to be improving the performance of Gomes' breaking pitches.

However, Gomes' arsenal has been constantly changing throughout his career, and 2015 has been no exception. According to Brooks Baseball's category classifications, his primary breaking pitch was a splitter in 2014, but in 2015, he has relied on his slider more in addition to the splitter. It is hard to tell if the increase in whiffs on his breaking pitches is from changing eye levels or new pitches, but either way, it suggests that Gomes is making strides toward improving his strikeout rate by missing more bats.

While they haven't been exceptional so far, high fastballs may still be a feasible option for Brandon Gomes. They would cause his fly ball rate to be magnified, and because Tropicana Field suppresses home runs, many of those would be caught in the outfield. While strikeouts haven't been a crucial part of Gomes' approach, high fastballs would lead to more whiffs, and push hitters into more unfavorable counts. Elevated fastballs aren't going to solve all of his problems, but if he can use them more effectively, it will be beneficial to his overall performance.

Overall, the high, rising fastball is a clear organizational strategy that has continued to be implemented during the 2015 season. The increase in perceived velocity has undoubtedly helped Rays pitchers, and those with high vertical movement measurements have been able to use their fastball shape to complement the elevated location. However, the results have been mixed. Jake Odorizzi, for example, has found success with it, but it has been ineffective for Brandon Gomes. It is difficult to pinpoint the component that makes it successful for one pitcher but not for another, and likely warrants a more in-depth study. But, as more pitchers around the league try to pitch lower in an effort to keep the ball in the part, it makes sense for the Rays to break the trend and continue to elevate pitches.

Statistics used are from FanGraphs, PITCHf/x data is from Brooks Baseball and Baseball Savant. Pitch Visualizations are from TexasLeaguers.com.