Checking in on Zack Thornton in Triple-A

The Mets acquired reliever Zack Thornton and a player to be named later for Ike Davis, who was once considered a franchise cornerstone, from the Pirates. One month later, what did they get and how does this look?

USATSI_7759586_110579513_lowresWhile Davis has hit .286/.388/.429 with two home runs, 14 walks and 18 strikeouts in 28 games with the Pirates, Thornton has been a reliable piece of the Triple-A Las Vegas 51s bullpen.

>> Read a Prospect Q&A with Thornton

In 12 appearances, Thornton has run a 2.30 ERA (4 ER/15. 2/3 IP) with 13 strikeouts and three walks. All three walks, and three of the four runs he has allowed, came in one bad outing against Tacoma on May 2. Since that blowup, he’s been nearly perfect in seven appearances: 8 1/3 IP, five hits( all singles), no walks and seven strikeouts. The PCL has hit .167/.167/.167 against him in their last 30 plate appearances.

So, how’s he doing it?

51s manager Wally Backman said that Thornton’s a right-hander with a lot of deception.

“He looks to be able to throw his slider anytime in the count when he needs to – to throw it for strikes,” the manager said.

Thornton throws out of a three-quarters arm slot.

“He’s not a power-armed guy, but he’s got pretty good sink on his fastball. Throws 90 miles an hour, with good sink and hitters don’t get a real good look at him. He gets a lot of guys out front and off balance because he’s got some deception,” Backman said.

The source of Thornton’s deception?

“He steps toward the third-base side and slings it across,” Backman said. “Hides the ball pretty well.”

Also working in Thornton’s favor: he can throw regularly as Backman described him as possessing “a rubber arm.” In the last two calendar weeks, he’s made seven appearances, at once point appearing in three games in four days.

Although he came to the Mets with a reputation as a ground ball pitcher, Thornton has not been especially proficient at inducing ground balls yet in his first 60 batters faced with Las Vegas.

………………LD%              GB%              OFB%           IFB%
Thornton        26.5               46.9                 16.3               10.2
PCL                18.2               43.7                 27.8               6.9
Source: MinorLeagueCentral.com

Thornton’s ground ball rate is just barely above league average. Given that he has not thrown that many innings overall, average is a reasonable estimate. While his line drive rate is 8 percent above the PCL mean rate, his outfield fly ball percentage is nine percent below average. Remember, we’re dealing with small samples. Also, essentially all of Thornton’s extra Iine drives come out of his outfield fly balls. And since we know that there are major data problems here with park effects and official scorer biases with regards to classifying fly balls and line drives (see Colin Wyers’ great work here and here), I’m inclined to suggest that Thornton’s bated ball mix roughly approximates PCL average.

For two years running, Thornton has performed significantly better against righties than lefties. This year, in 61 PA, righties have hit .214/.246/.268 against him while lefties have hit .324/.343/.441 in 35 PA. That’s consistent with his work last year spread between advanced Single-A, Double-A and Triple-A, when righties hit .172/.212/.244 in 193 PA while lefties hit him up at a .260/.294/.337 rate.

Thornton is fastball/slidder righthandeder who compensates for slightly below average fastball by throwing strikes with a funky delivery that gives right-handed batters fits. Lefties hit him hard. This could be a useful situational reliever profile.