MLB.com Columnist

Mike Petriello

Neris' unhittable splitter boosting Phillies bullpen

Second-lowest overall contact rate in baseball at 57.4 percent

Neris' unhittable splitter boosting Phillies bullpen

Most of the important names on Philadelphia's shockingly effective early-season pitching staff came from big-time origins. Aaron Nola was the No. 7 overall pick in the 2014 Draft. Jerad Eickhoff came from Texas in the Cole Hamels trade, and Vince Velasquez came from Houston in the Ken Giles trade. That's exactly how a rebuild is supposed to work: You draft well, and you collect young talent by trading away Major League pieces.

Of course, it also helps when a relatively unheralded internal option makes an unexpected big step forward, too. Philadelphia, meet Hector Neris, and his splitter of doom.

We say "meet" as though Neris didn't already appear in 33 games with the Phillies in 2014-15, but there's a big difference between the one who had a 3.70 ERA entering this season and the one who has allowed just two earned runs in 15 1/3 innings (1.17 ERA) with 24 strikeouts this year. Sometimes, these things can be very complicated. In Neris' case, it couldn't be simpler: He's taken his best pitch, and he's throwing it more.

That's essentially what Phillies manager Pete Mackanin asked Neris to do, anyway, saying, "We told him late in the spring to start throwing that split more than he has been." That's exactly what's happened. Last year, Neris threw the split 27 percent of the time, primarily focusing on his four-seam and sinker (approximately 30 percent apiece) and a slider (14 percent). This year, the slider is all but gone, having appeared just seven times, and the splitter usage has doubled, up to more than 50 percent.

The new Neris has been so effective that of the 266 pitchers with 10 innings in 2016, only one has been more difficult to make contact against.

Lowest contact percentage in 2016 (minimum 10 innings)

1. Seung Hwan Oh -- 57 percent
2. Neris -- 57.4 percent
3. Felipe Rivero -- 62.5
4. Pedro Strop -- 62.9 percent
5. Craig Kimbrel -- 63 percent

The next two names on that list: Andrew Miller and Dellin Betances. It's a great place to be.

So why has Neris suddenly become so hard to hit? Well, we have numbers, and we'll share those numbers, but perhaps nothing will get the point across more effectively than to simply show what he did to Michael Conforto with the splitter in April:

Hector Neris K

Since the start of 2015, Neris has thrown the splitter 292 times, and allowed six hits on it, collecting 42 strikeouts -- which is a .092 average. It's been so dominant that if we look at the seasons (since 2008) with the highest percentage of swinging strikes on the splitter, Neris actually shows up twice.

Highest swinging strike percentage, splitter, 2008-16

1. Manny Parra (2013) -- 69.8 percent
2. Brandon League (2009) -- 67.4 percent
3. Neris (2016) -- 62.5 percent
4. League (2010) -- 51.1 percent
5. Neris (2015) -- 52.5 percent

So what makes that splitter so good? A few things:

He throws it hard, with low spin. The Major League average split-finger last year was 84.8 mph, with 1,524 rpm of spin. Neris' comes in at 86.5 mph (ninth of the 29 pitchers with 10 this year) and at 1,414 rpm. Lower spin should help a pitch dive, and that's exactly what Neris' does, because …

It moves like few others. The vertical movement on Neris' pitch is -0.6 inches, which is the second- owest -- low being a good thing here, as you want the splitter to fall, not stay up -- in baseball this year. (Most pitchers have a positive number there, as the ball drops less.) But what's most important is that since he gets 9.5 inches of movement on his regular fastball, there's a 10-inch difference in drop there, which is what makes all the difference, because...

It looks like his fastball, right up until it doesn't. It's just not the movement on a splitter that makes it so effective. It's that the batter sees it as being a straight fastball, until it falls off the table and he swings right over it -- exactly as Conforto did. But that only works if the pitcher releases the pitch from the same point, because if the hitter is tipped off in some way that the splitter is coming, he can hold off.

Neris was good enough on that front last year, but he's improved that so far in 2016:

Neris is releasing his splitter and his four-seam very similarly in 2016, making the split more effective.

To the hitter, the two pitches look the same coming out of Neris' hand. They look the same for much of the way to the plate, and then while one stays up, the other slams into the ground, with movement unlike most other splitters. It's a tremendously valuable weapon, one that Neris is putting to great use. Sometimes, it doesn't have to be complicated. It's just a matter of realizing what works, and going with it -- and it's yet another thing that's gone right for the Phillies in the early going.

Mike Petriello is an analyst for MLB.com and the host of the Statcast podcast. This story was not subject to the approval of Major League Baseball or its clubs.