Ron Marinaccio’s mechanics aren’t quite right

Ron Marinaccio started the month of May strong after a stellar April. On May 6, after 1.1 scoreless innings against the Rays, his WHIP dropped to a dominant 0.85. He looked as though he was continuing to improve after a great rookie campaign, cementing himself in Aaron Boone’s circle of trust.

He hasn’t been quite right lately, though. His first career save in Thursday’s game notwithstanding, the righty has struggled to put hitters away in his last six appearances. My colleagues have discussed the fan base’s trust in Marinaccio and some of the concerning problems in his numbers. Walk rate as usual has a lot to do with his ugly lines the past few times out. Here though, I’m going to focus on his mechanics, pitch shape, and the struggle to use his sweeper effectively.

Marinaccio gave up four earned runs in 0.2 innings total during consecutive appearances against the Rays on May 11th and 13th, and he imploded on May 16, giving up three runs to the Blue Jays in an inning of work. Luckily, the team picked him up for a Yankees victory, but such erratic results are inconsistent with who Marinaccio has typically been in pinstripes.

The right-hander’s mechanics are geared toward his excellent changeup. To throw a good changeup, your mechanics must be on time. Open up the hips too early, and it’ll float over the plate and beg the hitter to demolish it. Stay closed too long and it’ll run away into the other batter’s box. Marinaccio has a loose arm path that lends itself well to changing speeds, but it has to be synced up properly to attain the two things he needs on the pitch — velo deception and two-plane break. Because of this, it’s vital for him to repeat the mechanics not only with his fastball/changeup combo but with his sweeper in order to be effective against both righties and lefties.

He hasn’t landed his breaking ball enough for strikes and it’s handicapping his other offerings. His changeup location has been an issue, but when hitters can stay back and look low in the zone rather than worry about covering the outside corner, the changeup becomes less effective.

Swing percentage also tells the tale of too many non-competitive sweepers down and away to right-handed batters. The low-and-away out of the zone spot is the most favorable swing and miss possibility for Marinaccio’s sweeper. Because he’s off slightly on his mechanics, hitters see the pitch longer, and he doesn’t throw it for a strike often enough to make hitters think twice about taking it.

His whiff percentage on the pitch has suffered, decreasing from 29.4 percent last year to 25 percent this year. Hitters are picking it up better out of the hand and laying off it easily.

Let’s look at the mechanical problems that lead to his sweeper missing location. Here’s a nasty changeup to put away Brandon Lowe on May 14th. Watch his upper half at the moment his front foot lands.

This example represents Marinaccio’s ideally repeatable mechanics. He’s driving straight down the mound with shoulders squared and balanced. When we look closely, there’s a quantifiable difference in his mechanics on the sweeper. This pitch against the Blue Jays lands on the other side of the spectrum.

On this miss to Whit Merrifield, Marinaccio’s center of gravity at foot strike is slightly different, and it throws off the entire delivery. His release point drops down from 5.3 feet from the ground on his fastball on average to 4.9 feet on the sweeper. Even from the broadcast angle you can see him working around the ball rather than over it.

To put it in plain terms, it looks as though he’s guiding the sweeper. His changeup is so effective because it has the same arm speed and release point as his fastball. He hasn’t been able to replicate this deception — he changes his mechanics noticeably on the sweeper and any hitter can see that in the on-deck circle.

These images are at release point, and he’s standing up noticeably straighter on the sweeper to Merrifield, which puts him in a less athletic position at release point. He then has to drop the release down to generate movement, and the pitch misses badly.

It’s a bit difficult to see because of the slightly different camera angles in each stadium, but Marinaccio is in a much more athletic position as he uncoils for release, and is in a position to create organic movement on his sweeper without having to work under it with his wrist.

His performance Thursday suggested that this may have been only a temporary hiccup. A lower walk rate will go a long way to make the sweeper more effective when the hitter has to protect with two strikes. For Marinaccio, it’s all about letting that changeup shine, and the sweeper needs to get better in order to complement it.