Niese and Pelfrey roll the dice

"I guess my luck ran out." -- Mike Pelfrey after his 10-0 loss to the Phillies on May 1

Funny that he brought that up, because Pelfrey's "luck" has been a popular topic in baseball's statistical blogosphere this season.

In that May 1 loss, his luck was bad -- in this case, in the form of a couple of defensive miscues (both were scored hits). Was it Pelfrey's fault that Alex Cora and Jose Reyes couldn't hang onto popups, setting up an ERA-shredding six-run fourth inning in the loss to Roy Halladay and the Phillies?

For that matter, by most accounts, Jonathon Niese -- who starts tonight against the Nationals -- pitched pretty well in beating the Phillies to close out April. But if Jason Bay and Jeff Francoeur didn't make stellar catches early in the game, or if the balls had traveled a couple of feet further and the Phillies had scored a few runs, would your opinion have changed? Niese's ERA benefited because his defense did a nice job behind him.

Some of you may be a bit leery of the newfangled stats that have recently become popular in the baseball community. But these stats can help explain what happened for and against Niese and Pelfrey in their past two starts. Niese had some help from his friends behind him. Pelfrey did not.

There are a few stats that attempt to cut to the chase with regard to a pitcher's control of what happens around him. One is called BABIP (Batting Average on Balls in Play). Another is called FIP (Fielding Independent Pitching). Both operate on the same premise: that pitching performance can be sorted into two categories. One category includes three stats: strikeouts, walks and home runs. The other includes everything else.

BABIP looks at the "everything else" part, with the premise being that regardless who is pitching, if the ball is hit, and not hit out of the ballpark, you're going to give up a hit around 30 percent of the time.

If you're giving up hits less than 30 percent of the time, there are a few things to look at. You may be getting a lot of ground balls (which tend to be outs more often than not), you may be getting help from your defense, or you may have been lucky. Perhaps your fielders got in the way of a couple of hard-hit line drives or ground balls and turned them into outs.

If you're giving up hits more frequently than the 30 percent rate, you may be giving up a lot of line drives (which are hits, more often than not), you may be getting hurt by your defense or you may be a little unlucky (you may have been beaten by bloops).

Or you might not be a good pitcher, in which case you're not going to last long in the major leagues.

Pelfrey spent the majority of April with a BABIP in the low-to-mid-.200s, a contrast to the .302 and .321 he posted in 2008 and '09. His rate of giving up line drives and fly balls was pretty similar to what it was in those two seasons. So the conclusion to be drawn was that Pelfrey was due for the numbers to catch up with him. The law of averages said some of those balls being put into play would eventually find holes.

Against the Phillies, it caught up to him. Pelfrey did his job, getting weakly hit popups. He just didn't get outs from them. The mathematical breaks of the game broke against him, and a disastrous inning resulted.

Niese was working from the opposite end of the spectrum when he faced the Phillies and pitched a gem. His BABIP was rather hefty (it's still at .387), partly due to being pummeled in Colorado on a day in which his curveball wasn't working.

That day versus the Phils, two plays were made for him and his BABIP. Those who buy into BABIP will tell you that Niese was simply due for some good defense or some good fortune, since there were no other statistical signs that he was out of sync.

The companion stat to BABIP, FIP, evaluates pitching performance almost solely based on strikeouts, walks and home runs allowed. Think of it this way: Those are three things that Pelfrey and Niese have more control over than whether Reyes or Cora will hang on to a popup.

FIP takes a highly educated guess at what your ERA should have been, weighting your strikeouts, walks, and home runs allowed, then combining them into one number, with a slight adjustment made to account for the overall major league ERA at the time. FIP even has its own companion stat -- xFIP, which goes a step further and looks at how often your fly balls are home runs.

If you want to make judgments with FIP and xFIP, think of it as being on a scale similar to ERA, and then use it in conjunction with ERA. A 2.00 is off-the-charts good. A 3.50 is pretty decent. A 5.00 is mediocre at best.

Niese currently has a 3.60 ERA, a 3.73 FIP, and a 4.06 xFIP.

A little confused by the numbers? Don't be. Here's the deal: Niese has given up 37 fly balls so far, but only three home runs (two coming against the Reds on Wednesday). FIP basically operates on the premise that he can maintain that kind of performance. xFIP thinks that will be difficult, and that he'll do a little worse down the road.

What will bear that out is time, and a larger sampling of Niese's work. Give it a season's worth of starts and we'll have a better idea of whether Niese can keep the ball in the park as often as he has been. Most pitchers can't. Last Wednesday, the balls that didn't leave Citizens Bank went a little further and flew out of Great American Ball Park in Cincinnati.

In Pelfrey's case last season, he had an ERA of 5.03, a FIP of 4.39 and an xFIP of 4.52. Basically what that meant was that Pelfrey didn't deserve the ERA with which he finished. FIP is believed to be a good predictor of future success, meaning that Pelfrey should expect an overall ERA drop for this year.

Likewise, the FIP family also indicated that Pelfrey didn't necessarily deserve the stats he put up in the first four starts of this season, when his ERA was sub-1.00 and his FIP was over 2.00. In all fairness, that level of performance would be hard for Dwight Gooden circa 1985 to maintain.

There's still a decent difference between Pelfrey's current 2.65 ERA, his 3.21 FIP and his 3.96 xFIP, so there may be more starts to come similar to that one versus the Phillies. It will be up to Pelfrey to battle through not just any health issues he may be facing (re: the MRI he had last week), but some baseball mathematics as well.

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Mark Simon is a researcher for Baseball Tonight and a frequent contributor to ESPN New York's Mets blog. He's very worried about David Wright.