Pitchers with a 1.25 ERA are rarely the subject of a "What's Wrong With ____" article. Neftali Feliz is different. Feliz blew three saves against the Royals in a little more than a week and left many wondering why.
Dave Cameron of fangraphs.com wrote a very interesting piece looking into what had changed with Feliz. Cameron explored Feliz's very odd splits when facing right handed and left handed batters. At the time Cameron penned his article, Feliz had yet to strike out a single right handed batter this season. He did finally break that streak with a strike out of Jeff Francoeur on May 27th, but that remains the only right-handed strike out for Feliz. Clearly, something odd is going on. Cameron's piece sums up his investigation in a simple sentence: "Usually, I’d like to propose some kind of theory as to what might be going wrong, but I honestly have no idea."
Cameron's theory would likely be based on one of lesser stats that are often used to explain a pitcher who is suffering from a sudden change in performance, such as velocity, movement, pitch selection, etc. The only one of these stats that could explain Feliz's performance change, as noted by Cameron, is a slight "straightening" of his fastball. Essentially, Feliz has less movement along the horizontal plane than he has shown in the past. As Cameron notes, this doesn't explain why Feliz only has problems against righties because lefties should be able to hit a straight fastball too.
Following the rabbit trail a bit deeper, the cause may be a simple matter of release. One change in the Pitch F/X charts for Feliz, while subtle, is a drop in his release point.
For a visual comparison, here is a chart showing Feliz's release point for the pitches from his blown save on May 19th of this year against the Royals:
Compared to a game, also against the Royals, from May 25 of last year:
The difference is slight, but noticeable. The question then becomes, why is the release point lower. A lower release point could be a sign of a Feliz dropping his arm slot, but that would be accompanied by a coordinating horizontal movement of the release point, which doesn't exist here.
The problem could be a result of Feliz "short arming" his pitches, in other words throwing without fully extending his pitching arm. At times that can be caused by a pitcher dealing with an injury and Feliz has already had one stint on the disabled list this year. Overstriding, a longer stride while delivering a pitch, could also cause a lower release point.
To see how Feliz's release point affects his movement and further investigate what the root cause might be, here is a chart which shows the horizontal movement and velocity of pitches for the May 19, 2011 game:
Compared to the similar chart from the May 25, 2010 game.
A "straight" pitch will appear close to the center vertical line on each chart. The further away from that line, in either direction, the greater the movement on the pitch. As can be seen from the two game charts, Feliz's pitches have less horizontal movement during his 2011 game than they did during his 2010 game.
Feliz's 2011 velocity does appear to be lower, but only slightly so. While this may make the "short arming" theory a possibility, the difference would likely be greater than one or two miles per hour if a pitcher were truly dropping his release point as a result of "short arming." Feliz may be compensating for that in other parts of his mechanics, so "short arming" can't be ruled out, but the velocity drop could also be accounted for by usage, number of pitches, or a host of other reasons.
The most likely culprit of the lowered release point seems to be a longer stride. Overstriding lowers the pitchers body frame which thereby lowers his release point. Overstriding also affects other parts of a pitcher's game, chief among them is control. Since Feliz is currently walking batters at nearly double the rate of his career average combined with the lower release point, Feliz's stride becomes a key suspect in his recent struggles.
The bad news is that a host of other minor adjustments or changes could be causing Feliz's release point change, which will not always reveal themselves in sabermetric charts and graphs, but in this case some obvious culprits are at least visible for the Rangers staff to investigate.
The good news for the Rangers is that even with a lessening in his movement and his control, Feliz has been able to put up a 1.25 ERA.
The better news would be if the only reason for Feliz's struggles were a simple mechanical issue such as overstriding, as opposed to a looming major health issue.
The best news is that the Rangers have one of the game's best pitching coaches. If a mechanical issue is plaguing Neftali Feliz, Mike Maddux will find it. My advice to Maddux...take a look at the stride length.