The Tigers just signed Mike Pelfrey to a two-year deal worth $16 million. The big right-hander has a good fastball, a penchant for licking his fingers, and a split-finger that’s decent for grounders, but he still shows up on the bottom of an important leaderboard. Despite that, he’s been an average major league player four times in his career, and he’s projected to be worth the deal.

Turns out, he has one ability that is elite. And if he continues to display that skill, the Tigers will have made out on this short deal.

Last year, among pitchers that threw at least 160 innings, Pelfrey had the worst strikeout minus walk rate in baseball. That comes with the second-worst strikeout rate, and the slightly above-average control couldn’t make up for it.

Up the sample, and the results are the same. He’s third-worst in baseball in strikeouts minus walks since 2007. Only Livan Hernandez and Kyle Kendrick have thrown 1000 innings since then and struck out fewer batters. And because strikeouts and walks are so important to most pitching metrics, he’s bottom-three in SIERA and bottom-five in xFIP, and the only active pitcher worse than him in multiple spots is Kendrick, who was paid $5.5 million last year and may not have a job ready for him after the season he had last year.

He’s only bottom-20 in FIP, though, and that’s mostly because his home run rate (0.72 per nine) is better than average. He’s actually top-four, in a good way, when it comes to home runs per fly ball. Only Clayton Kershaw, Adam Wainwright, and Justin Verlander have shown a better ability to suppress the home run.

As exciting as those names are, you have to look to the group just behind Pelfrey for a more sobering appraisal of this skill: Chad Billingsley, Matt Cain, and Jered Weaver all showed this skill for a while, and then lost it, sometimes in spectacular fashion. Cain, in particular, inspired a series of posts from Dave Cameron and others on suppressing home runs.

The one-sentence sum of those pieces is: you probably can’t suppress home runs per fly ball reliably, at least not for long. That’s why it takes 9.4 years — more than nine years! — for a pitcher’s home run per fly ball rate to stabilize. Pelfrey has actually crossed that threshold, since he’s allowed 1287 fly balls, when 1234 was the number Derek Carty found.

But it’s important to remember what stabilization means. It means that, going forward, the pitcher’s demonstrated ability in home run suppression is just as important the league average. So, even though he’s shown some skill, he’s not likely to show that same exact skill going forward. And, if his walk rate regresses to his career rate, Pelfrey will end up being a replacement level pitcher, under contract for two years at the price of about a win.

On the other hand, the Tigers may have a different idea about home run suppression. Maybe they see enough in the sinker and splitter to believe in old-fashioned home run suppression (ground balls). At least the bet they’ve placed on this skill is a small one, relatively.