James Shields, by my estimation, has been the Kansas City Royals best starting pitcher so far this season. That's to be expected, since the front office surrendered some serious talent to acquire the starter, and Shields experienced the most recent major league success out of all Royals starters.
Ervin Santana, however, has been nearly as effective as Shields, which is a more shocking development. Santana pitched horribly last season, and I wrote an article claiming that his chances of rebounding to become even a 1-win pitcher were low.
It's still far too early completely change our assessment of Santana, but so far the right-handed starter has performed quite well. Santana's Pitch F/X numbers reveal some changes about how he has pitched this season, and the results stemming from those changes have been successful. There is no reason to assume that Santana can keep up his 2.48 ERA, but he has a FIP of 3.64 and an xFIP of 3.48. If he can continue to throw a high number of innings with an FIP in the mid-3's, Santana will provide the Royals with a lot of value.
To see his change in approach, we first need to look at the pitches he threw last season. The table below (data taken from texasleaguers.com) is all of the pitches that Santana threw last season, according to Pitch F/X:
FF=Four-seam fastball, SL=Slider, FT=Two-seam fastball, CH=Changeup
Santana, as you have likely noticed, is mostly a fastball/slider pitcher. His slider is his most effective pitch, as it easily causes the most whiffs. The right-hander did not have enough control of his four-seam fastball or his changeup last season to consistently set up his slider, which hurt his effectiveness.
There are two noticeable differences between Santana's 2012 Pitch F/X data and his 2013 data so far. Santana has thrown his non-slider offerings for strikes with much more consistency, which helps set-up hitters to chase his slider. He has also thrown his slider and two-seam fastball more often, a combination of pitches that compliment each other quite well.
56% of Santana's pitches are still fastballs, but he uses his two-seam fastball more frequently and much more effectively. He only threw the pitch 30 times last season, but has already thrown it 41 times in 2013.
His slider compliments the two-seam nicely. If thrown properly, it will look very similar to the two seam fastball before breaking the opposite direction that the two-seam fastball breaks; down and in to left-handed hitters but down and away to right-handed hitters.
Mendoza throws his two-seam fastball much more frequently than Santana, but Santana throws his four-seam fastball and slider more effectively than Mendoza. Santana, so far, has used his two-seam fastball to keep batters honest, throwing it often enough to keep the hitter from sitting on his four-seam fastball.
His four-seam fastball has not lost any velocity from last season, but his two-seam fastball has. The table below presents his fastball velocity from 2012 and his first four starts of 2013:
Normally, decreased fastball velocity sends up warning signs of a pitcher in decline. In Santana's case, however, I think it is actually a positive development that his two-seam fastball has lost velocity. Pitchers normally throw their four-seam fastball harder than their two-seam fastball; the fact that it was inverted with Santana in 2012 suggests he had not mastered the pitch properly.
Santana's two-seam fastball is moving around an 1.5 inches more horizontally and almost 2 inches more vertically this season that it did last season. Trading the velocity for the extra movement helps distinguish the pitch from his from his four-seam fastball, giving Santana a more diverse arsenal.
Of course, his increased use of a more effective two-seam would hardly matter if Santana was not locating his pitches for strikes with more consistency. He has thrown all three of his non-slider offerings in the strike zone more frequently than last season, which allows him to use his slider in advantageous counts. That has led to more hitters chasing sliders outside the strike zone, increasing the whiff rate of the pitch.
I don't have an explanation for why Santana is locating his pitches more effectively this spring. It certainly could be a string of quality starts that will not sustain over the course of the season. He may be healthier this season, or fixed a mechanical flaw in his delivery, or been more devout in his prayers over the off-season. Whatever the reason for his increased strike percentage, it has also played an important role in his success so far.
Comparing his statistics from last season to 2013 illustrates the obvious: throwing more strikes and quality pitches leads to better results:
The increase in strikeouts and decrease in walks is easily the most encouraging results Santana has produced so far. Strikeouts and walks tend to stabilize for pitchers more quickly than other statistics, so they are important indicators for how much a pitcher has improved.
Santana's early season statistics also contain some curiosities, which should help remind everyone how early in the season it is and that we need more data before coming to definitive conclusions. His BABIP is higher than last season's despite the fact that hitters are hitting more flyballs; flyballs have a lower BABIP than groundballs. Of course, home runs don't court towards BABIP, so the fact that Santana allowed so many home runs last season drove his BABIP down.
I would also feel better if Santana's HR/FB% fell to his 10.8% career average, but again, it's very early. No one will ever confuse Santana for Matt Cain, but as long as he avoids last season's abysmal numbers, he should be fine.
It will be interesting to see how effectively Santana continues to mix in his two-seam fastball and with what frequency. I have my doubts that he will be able to maintain his sub 5% walk percentage, but as long as he keeps striking hitters out, he can afford to surrender a few more walks. A new and more effective pitch in his arsenal should help keep hitters guessing this season.
The Royals revamped pitching rotation continues to take on a more important role this season for every game that the lineup continues to flounder. While Santana should not be expected to keep a sub-3.00 ERA, a 3.75 ERA over 200 innings would have been way more than most Royals fans would have dare to dream of before the season. Four good starts shouldn't cause anyone to drastically change their opinion on Santana, but the increase in control and complimentary two-seam fastball should inspire hope that Dayton Moore acquired a quality starter for Brandon Sisk this off-season.