- FanGraphs Baseball - http://www.fangraphs.com/blogs -

The Greggster

Toronto’s signing of Kevin Gregg this offseason to a one-year deal with a club option was a bit puzzling, given that a) he’s a reliever, and b) rebuilding teams generally shouldn’t spend money of veteran relievers. Moreover, the Blue Jays already had at least two pretty good relievers in Jason Frasor and Scott Downs, as well as players like Josh Roenicke (who came over as part of the Scott Rolen trade) waiting in the minors. But with a little thought, it became clear that not only was the Gregg contract not all that onerous, but that Frasor and Downs, as free agents after 2010, would both be good trade chips, and that Gregg, while perhaps not spectacular, could help hold down the fort.

He has done a bit more than that so far, moving into the closer’s role not long after the season started and handling the highest-leverage situations on the team (2.05 game LI). Gregg’s 2.12 ERA is not deceiving. He has a 2.09 FIP, and it’s not build on a house of fly ball luck, either, as his xFIP is 2.37. His 1.70 tERA is aided by a 10.5% line drive rate that is probably unsustainable, but clearly, Gregg has had a authentically good run so far this season.

Gregg hasn’t had a full-season xFIP under 4 since 2004, so we should look a bit closer. So far this year, Gregg is getting more strikeouts and avoiding walks better than ever before, which are obviously Good Things. He’s not getting lucky against lefties, either, as Gregg actually has a reverse split for his career — a career xFIP versus righties is 4.49, and 3.92 versus lefties, and that’s continued in 2010 with a 3.14 versus righties and a 1.26 versus lefties. What really stands out for Gregg in 2010 is his ground ball rate. Prior to this season, Gregg fluctuated between about average and greater-than-average groundball rates, but so far in 2010 ground balls have been a major key to to his success — 55% of balls in play have been on the ground. As Ric Flair might ask, “what’s causin’ all this?”

On this blog (and this podcasts) and elsewhere, there has been on-and-off talk of the cutter being a “miracle pitch” that more pitchers should add to their arsenal. Through 2009, BIS pitch types record Gregg has throwing almost no cutters. Guess what? In 2010, about 30% of his pitches have been identified as cutters. I haven’t read anything about Gregg talking about adding a cutter, and I’ll leave it up to BIS and the Pitch F/X experts to decipher, but whatever is going on, it is likely connected with Gregg’s better ground ball rate this season.

Let me emphasize for the nth time that all player performance is subject to random variation that can exaggerate changes over a short periods of time. This has to be keep in mind with relief pitchers in particular, given that even their full-season sample is so much smaller than everyone else’s. That being said, if Gregg has discovered something new that helps him keep the ball on the ground, he could not only be an good stopgap for the Jays when they trade their other veteran relievers, but he could become a valuable trade chip for a rebuilding Toronto club himself.