Collette Calls: The Ups and Downs of Whiff Rates

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Updated on April 28, 2015 12:10PM EST

Last week, I mentioned the stabilization rate of statistics and that we're still at a rather low amount for any stat save strikeout rate for pitchers. Since we have quite a number of pitchers who have faced at least 70 batters, let's look at how some pitchers are showing extreme gains or losses with strikeout rates and why.

Biggest gainers in Strikeout rate from 2014 to 2015:

PITCHER	2014 K%	2015 K%	DIFFERENCE
Brandon McCarthy	21	35	14
Trevor Bauer	22	35	13
Clay Buchholz	18	29	11
Chris Archer	21	31	10
Joe Kelly	16	25	9
James Shields	19	28	9
Lance Lynn	21	29	8
Francisco Liriano	25	33	8

Brandon McCarthy's ascension is the most stunning as most of us thought he had reached his apex once he joined the Yankees last year and dusted off the cutter that the Diamondbacks took away from him. Instead, McCarthy did what another guy did on this list and began throwing more four-seam fastballs and fewer cutters. That helped McCarthy throw with more velocity this season with the Dodgers and get more strikeouts as the four-seam is a swing-and-miss pitch while the sinker is not. Unfortunately for his ratios, those pitches tend to be up in the zone and can be hit for homers, which was a problem for him this season. Worse still, McCarthy suffered a torn UCL in his last start and likely is headed for season-ending Tommy John surgery.

Trevor Bauer is known as

Biggest gainers in Strikeout rate from 2014 to 2015:

PITCHER	2014 K%	2015 K%	DIFFERENCE
Brandon McCarthy	21	35	14
Trevor Bauer	22	35	13
Clay Buchholz	18	29	11
Chris Archer	21	31	10
Joe Kelly	16	25	9
James Shields	19	28	9
Lance Lynn	21	29	8
Francisco Liriano	25	33	8

Trevor Bauer is known as one who throws just about every pitch in existence. One of the reasons he has improved this season is he has shelved a few of his pitches while increasing the use of his swing-and-miss pitches. He has added more two-seamers, but as a pitch that he is running to the front and back door of the plate (go back and watch his start against Houston) and then quite a bit more sliders and changeups. His control can come and go at times, but his strikeout potential remains strong.

That brings us to my boy, Cletus Spuckler in Boston. Clay Buchholz is making #TeamCletus proud with his strikeouts this season. Buchholz's improvements have come from him retooling his changeup and evolving it from a four-seam grip to a grip he used in the minor leagues. He is using the pitch more frequently this season with his additional confidence in the pitch. The new grip is also giving him more vertical drop on the pitch as well as some horizontal movement. As he displayed against the Yankees a short while ago, he is still quite capable of laying a stinkbomb on your ratios, but the swing-and-miss is back in his game.

That brings us to the incredible start by Chris Archer. Now with five starts under his belt, he has a 0.84 ERA, a 0.74 WHIP and a 37:6 strikeout to walk ratio while allowing 18 hits in 32.1 innings. Archer has always been the guy with the very live, if not erratic, fastball and biting slider, but he's slowly eased the cambio into his matchup. This was covered last week in detail and he continued it Sunday in dominating the Blue Jays once again. Between that and his improved sequencing, batters are mostly guessing at what he is going to throw as he generates many defensive swings. The ratios will undoubtedly climb, but a 200-plus strikeout season is within his reach the way he looks now.

Joe Kelly's strikeout growth follows the plan of attack Brandon McCarthy has used this season. Kelly also shelved his sinker and has more than doubled the use of his four-seam fastball while tripling the use of his slider. Kelly is now working 95-97, which has helped the whiff rates on his secondary pitches. His command is still spotty at times, as was the case in his most recent outing against Tampa Bay. The strikeout rate has gone from below league average to well above league average, and he was dirt cheap to roster on draft day.

James Shields is a veteran who continues to do what he always does. His pitch usage has not changed that much outside of increased use of his four-seam fastball in a more comfortable home park. His gain can be credited to a first full exposure to National League hitters and getting to face the pitcher as well as pinch-hitters later in games. Then you have Francisco Liriano who is doing nothing differently in terms of pitch utilization, but continues to strikeout at least seven batters per outings this season. Liriano has always been rostered for strikeouts, but this rate is unsustainable with no change in process. Pitchers do not go from mid 20s to low 30-percent strikeout rates without changing something. This looks more like matchups than anything else. Lance Lynn promised us that he was going to use his changeup as a difference-maker in 2015. He has barely used it, but he was already getting strikeouts without the pitch in his career. Plus, he's having a pretty darn good season thus far with the same approach he used in 2014.

Conversely, here are the pitchers who have had the biggest drop in strikeout percentage from 2014 to 2015.

PITCHER	2014 K%	2015 K%	DIFFERENCE
Alex Wood	25	12	-13
Shane Greene	24	12	-12
Jordan Zimmermann	23	12	-11
Kyle Gibson	14	4	-10
J.A. Happ	20	11	-9
Wily Peralta	18	10	-8
Chris Sale	30	22	-8
Madison Bumgarner	25	17	-8
Jeff Samardzija	23	15	-8
Stephen Strasburg	28	20	-8

Most of the pitchers drafted on this list were drafted for their strikeouts, so this list is likely quite a sore spot for many fantasy owners. Alex Wood is throwing fewer secondary pitches and more sinkers. The whiff rate on all of his pitches is down across the board as batters are not chasing his pitches as much as they did last season nor are they swinging as frequently as they did in 2014. Shane Greene's velocity is down slightly from where it was last season as a swingman, but the biggest difference is the whiff rate on his changeup is way down thus far. Jordan Zimmermann's pitch mixture is essentially what it has always been, but the whiff rates on his breaking balls are well off their historical rates. More concerning is the fact his overall velocity is down and some of his recent comments sound more like a rookie pitcher than one in his walk year. Wily Peralta is also struggling with his velocity, which is making his stuff more hittable.

Kyle Gibson was not drafted as a source of strikeouts, but he is not rosterable in any format if he is going to strike out so few batters. J.A. Happ may be pitching to the ballpark, but as his secondary numbers regress, he must start missing more at bats or it could be J.A. Crapp all over again. Happ's case is weird in that he has retained the velocity from last season and is still getting decent whiff rates on his pitches. His main issue is that he has tripled the use of his cutter from last season and is settling for weaker contact over strikeouts. Chris Sale came back from his injury quicker than expected, which is likely the issue with his rate. While his strikeout rate has not been amazing, it has still been better than the league average for starting pitchers.

Madison Bumgarner's issues appear to be more matchup based than anything as he is throwing more four-seamers and curveballs with similar velocity to 2014 but is not getting his historical swing-and-miss rates thus far. Jeff Samardzija's velocity is down a little from 2014 and so far, has utilized more cutters than splitters. Finally, Stephen Strasburg's whiff rates are down across the board on his pitches despite similar velocity and pitch utilization. Like Bumgarner, this could be matchup based more than anything.

All in all, it is important to remember that past performance is not a predictor of future success. We've seen enough of these pitchers in 2015 to see a change in process for some while others are fighting through matchups, process or decreased velocity.