Collin McHugh Continues to Trust His Slider

On Wednesday, Collin McHugh pitched well against the Ben Zobrist-less Oakland A’s. Zobrist’s absence made the A’s a weaker version of themselves, but they were still a tougher opponent than the hapless Rangers he saw five days earlier. While McHugh only tossed 5.2 innings and faced just 23 batters, he tied Trevor Bauer for the single-game strikeout lead for 2015 with 11. Although unlike Bauer, McHugh walked zero A’s instead of five Astros.

This is largely noteworthy because Collin McHugh was one of the most prominent breakout players from a year ago, and we’re dying to know how much of that breakout we should take to heart. In 2014, McHugh was a 3-4 win player, who could have been a solid number two starter on almost any team in the league and he posted those numbers in under 160 innings. If McHugh is actually that able, the Astros have five more seasons of a very good pitcher who can help anchor their next playoff rotation.

We all know about sample size, so most of us were cautious about McHugh heading into the 2015 season. He was a very low Mets draft pick and was waived by the Rockies before the 2014 season after showing no promise in his brief major league time. His minor league record was a bit of a mixed bag, but overall he had an ERA and FIP under 3.50 in 657.2 innings. McHugh wasn’t bad in the minors, but in his 2012 and 2013 major league appearances he was a home run magnet. He faced 224 batters across those two seasons and allowed a 1.049 OPS against. We have to acknowledge Coors Field, but he wasn’t any better with the Mets than with the Rockies.

In general, McHugh wasn’t a guaranteed bust when 2014 started, but the odds that he would turn into an above average starter were dwindling. Of course we know that he did, but pitching well over 25 starts and 154.2 innings doesn’t assure anyone that you’ll do it again, which is why many of us are intently focused on his early 2015 starts as we look for signs that what happened last summer wasn’t a fluke.

In his final ten starts of 2014, McHugh allowed fewer than three runs nine times and walked a total of seven batters while striking out 55. To give you a better handle on that run, it spanned 66 innings and resulted in a 1.77 ERA and 2.42 FIP. Add in those two nice 2015 starts and he’s up to 77.2 innings, 70 strikeouts, and 9 walks. Since August 1, 2014, Collin McHugh has basically been Clayton Kershaw.

Date	TBF	K%	BB%	HR/9	ERA-	FIP-
Before	590	22.0%	8.0%	1.39	138	114
After	300	23.3%	3.0%	0.35	45	58

While McHugh’s own mother probably wouldn’t project her son to keep up that pace, there are reasons to think he’s become a substantially different, and improved, pitcher. The thing that caught my attention was his shifting pitch mix. These are raw PITCHf/x numbers from his career before last August 1 and after, but the manually classified numbers at Brooks Baseball are largely consistent as you’ll see later.

Date	Fastball	Slider	Curveball	Changeup
Before	49.3%	22.6%	22.7%	4.9%
After	33.6%	38.3%	23.2%	4.8%

That difference is impossible to ignore, even though are samples are just about 2,300 pitches compared to 1,100.  In practical terms, the change in percentage shown in the table amounts to 15 more sliders per game since August 1. In that same time span, his fastball and slider velocity have ticked up about a half mile per hour for the heater and a mile and a half per hour for the slider.

He’s throwing both pitches harder and he’s giving hitters way more looks at the slider that he had previously. And maybe more interestingly, McHugh is throwing the slider more to righties and lefites (this time from Brooks Baseball).

Date	Slider vs RHH	Slider vs LHH
Before	27.5%	18.2%
After	42.0%	38.8%

The slider is generally a pitch that neutralizes same-handed hitters, but McHugh started fearlessly throwing it to lefties late last year. I don’t generally like to put too much weight behind pitch type linear weights individually because they’re all so interconnected, but observe McHugh’s pitch type run values per 100 pitches using the same August 1 split.

Date	Fastball	Slider	Curveball	Changeup
Before	-1.90	-0.12	1.56	-0.66
After	0.23	2.82	0.93	-0.79

This isn’t terribly predictive or even that helpful retroactively, but the slider clearly became a more effective pitch, even if you can’t ascribe the entire 2.7 run per 100 bump to an independent slider effect. He threw them in a pretty similar location to righties on both sides of the split, but he stopped throwing it down and in to lefties:

It’s still too early to say that McHugh has definitely become an All-Star caliber pitcher, but anytime a significant improvement in performance corresponds so neatly to a clear change in a player’s game, it supports the idea that the improvement is legitimate. McHugh started throwing more sliders, and harder sliders, and batters weren’t able to do much against them.

The evidence seems to outline a relatively clear cause and effect, but the even if we believe that McHugh is truly a different pitcher, we also know that the league will change around him. Major league hitters are savvy and they adapt to new things. It’s possible that McHugh didn’t get better, he just caught them off guard. It’s going to take another year or two to really nail down what Collin McHugh is as a major league pitcher, but early in 2015, it certainly looks like he’s following the formula that worked very well down the stretch last year.