On the Astros: Collin McHugh's second-best pitch is his slider

When Collin McHugh's success last year gets brought up, we focus heavily on effective velocity. The concept of pitch tunnelling was so new, it stuck out as why he was able to make such a leap out of nowhere.

Of course that bendy curveball would complement his four-seam fastball. Because batters couldn't tell which was which, they'd strike out more. That made sense.

Except we always forgot about how effective his slider has been.

This season, that's even more true, because McHugh's slider has been his most-used pitch through two starts.

Let's look at those starts to see how McHugh has been using his pitches and which ones he's getting most of his strkeouts on.

Thanks to the wonders of Brooks Baseball, we can see plenty of information on McHugh's two starts of 2015. For instance, the right-hander has thrown his slider 43 percent of the time this season. He's thrown his four-seamer 24 percent of the time, the curve 20 percent of the time and the change 13 percent of the time.

The slider itself clocks in about four miles per hour slower than his four-seamer, with less horizontal break than his 12-6 curve and more vertical drop than his change.

He also tends to use the slider when the batter is ahead. To right-handers this year, he's thrown the slider 65 percent of the time in those situations. Of course, he also throws that slider 45 percent of the time when he's ahead of right-handers and 43 percent of the time when he's got two strikes on rightys and 51 percent of the time when he's ahead of lefties.

That's a lot of percentages, but not real clarity. Basically, McHugh likes throwing his slider at any time. Why? Probably because it's his least-likely pitch to be outside the strike zone. While McHugh's other pitchers are strikes more often than not, his slider has only been a ball 26 percent of the time this year. That's a full five percent lower than his curve and 11 percent better than the fastball.

But, the real reason why McHugh might be relying on his slider is that it's a heavy pitch. Of the balls in play off his slider, 76 percent of them have been ground balls, easily the highest percentage of any of his pitches. Only 20 percent of balls in play off his slider have been line drives, which is the lowest percentage of any of his hits.

So, not only can McHugh rely on that slider to be a strike, but he also knows there's a good chance the batter will hit it on the ground. Is it any wonder that McHugh throws the pitch when he falls behind in the count? It's his best chance to get a strike or a ground ball.

His curveball is his "best" pitch. Batters just can't square it up for plenty of reasons (EV being at the top of that list). Last night, McHugh struck out seven of the 11 K victims on the curve. The other four, though, came on the slider.