The Lion Roars: Leo Nunez’s 2010 Awesomeness

After the 2008 season, the Kansas City Royals traded Leo Nunez to the Florida Marlins for Mike Jacobs, who was to become a key part of the Royals 2009 push for the AL Central title. There is no need to re-visit the fate of Kansas City’s aspirations. The Marlins apparently aren’t happy with how their own 2010 playoff push is going, firing manager Fred Gonzalez and some coaches today. I suppose owner Jeffrey Loria feels like being forced by the union and MLB to actually spend money entitles him to expect greatness from those under him. I leave that discussion for someone else.

But looking back at the 2008-2009 off-season, from the standpoint of the spendthrift Marlins, Nunez’s best attribute at that time was probably that he had one more pre-arbitration season left, and that they could get him for Jacobs, a replacement level player they were likely going to non-tender. Sure, Nunez had been a half-win reliever in 2008 with a 3.77 FIP, but while his 3.62 tERA looked good, his 5.13 xFIP was less than impressive. In 2009, while Jacobs (unsurprisingly to to nearly everyone everyone except the Royals’ “braintrust” and, it must be said, a number of FanGraphs commentators) was awful in Kansas City to the tune of -0.5 WAR, Leo Nunez didn’t exactly light it up in 2009, either, putting up -0.8 WAR. One could still say that the Marlins “won” the trade given the salary differential from the two, but this clearly wasn’t what they were expecting. Nunez wasn’t completely horrible, as his xFIP was 4.41, but a 4.91 tERA showed he was getting hit hard, his strikeout rate wasn’t making up for the big flies, and, frankly, given Florida’s usual budgetary methods, the predictable outcome would have been a non-tender rather than let Nunez head to arbitration. Florida obviously saw something they liked, however, and settled with Nunez for $2 million dollars.

Thus far in 2010, the Marlins’ faith in Nunez has been amply rewarded, we he’s put up almost one win already. What caught my eye, however, wasn’t simply Nunez’s good performance so far — after all, pitcher performance varies more year-to-year than hitters, and given the small samples we get of reliever performance in single seasons, great changes are to be expected from season-to-season since we only get a glimpse of their true talent. What grabbed my attention was how firmly Nunez seeming “transformation” is supported by his peripherals.

Beginning with the “dumb” stat, ERA: Nunez currently sits at 2.43. Over not even 30 innings, a lot of pitchers could do that. That is actually higher than his FIP, at 2.33. Nunez has had good FIPs before, partly on the basis of his luck on flyballs. He has been lucky with HR/FB rate this season, at only 4.0%, but even when normalizing that, his xFIP is still an impressive 3.04, and that’s mainly because of one of the most impressive and radical changes to Nunez’s peformance: after having about a 40% GB rate and about a 43% FB rate in 2008-2009, in 2010 Nunez has ramped up his ground ball rate to 52.6%w and his fly ball rate is down to 32.1%. All this explain why his tERA is an amazing 2.11 in 2010.

That isn’t all. In 2008, Nunez simply didn’t strike that many batters out (4.84/9). He increased that to 7.86 in 2009, but also upped his walk rate to 3.54. In 2010, he has lowered his walk rate down to 2.12, while increasing his K rate to 8.80, a career high if he keeps it up. Combining that with his newly-found groundball tendency, it’s as if Nunez looked at his 2009 in the offseason, wasn’t happy, and simply decided, “well, that didn’t work, maybe I’ll try striking out more guys, walking less, and, while I’m at it, I’ll keep half the balls in play on the ground. Maybe that will work.” I’m sure Brian Bannister has talked about it in one of the 27 interviews he’s given over the last few seasons, but Nunez is actually making it happen.

All of this is in an extremely small sample of course (not quite 30 innings), but keep in mind that it isn’t as if Nunez had a huge sample of last year’s performance, either, at about 70 innings. Using simple 5/3/2 weights for seasons, at about 42 innings we’d weight Nunez’s 2010 equal to his 2009 in terms of projecting his true talent, so he’s getting close. And there is evidence (other than the results he’s getting) that he’s changed his approach. His BIS pitch-types indicate that he’s throwing fewer fastballs and sliders in favor of many more change-ups, which has made his fastball and (especially) his change-up more effective. Whether he can continue with this success throwing almost 46% change-ups is something to watch.

We don’t know exactly what the Marlins saw in Nunez, but whatever it was, the made the right decision, and it is a credit to their talent evaluators. FanGraphs currently values Nunez’s 2010 performance alongside or greater than that of more well-known relievers such as Rafael Soriano, Billy Wagner, Francisco Rodriguez, Grant Balfour, Jose Valverde, Mariano Rivera, and Joakim Soria. Even if he can’t keep it up, he’s more than earned what the Marlins are paying him this season.

Matt Klaassen reads and writes obituaries in the Greater Toronto Area. If you can't get enough of him, follow him on Twitter.

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11 years ago

ERA is not a dumb stat. This is what is so off putting about Fangraphs. The condescending arrogance about your saber stats.

11 years ago
Reply to  QT

Dumb is in parentheses, its used here to show that ERA is not a good tool to predict future success. Also, if you are off put by Fangraphs, don’t read it…

11 years ago
Reply to  QT

ERA for relievers is typically a weak stat to use for relievers. Especially closers, who pitch very limited innings.