Pitchers Advanced Statistics: Keys to Analyzing Fantasy Trends

RotoBaller breaks down some advanced MLB statistics - keys for analysis of fantasy baseball hitters, trends and values - including BABIP, FIP, xFIP, HR/FB.


Advanced Pitcher Stats for Fantasy Baseball

One of the most misunderstood books in the last decade or so was Moneyball, the Michael Lewis novel about the Oakland A's that really brought advanced statistical analysis into the mainstream. A lot of people thought it was just about valuing On-Base Percentage looking at college players, but those were just examples of the overall concept. What the book was really about is how small organizations could take advantage of market inefficiencies and exploit tiny cracks in the system (the movie, on the other hand, was about making Paul DePodesta look as doughy as possible). The most important aspect of this was using statistics and knowledge, which in the market or in fantasy baseball is its own form of currency.

But it is a relative currency - it's value goes down as more people acquire it. If you have information about Amalgamated Widgets buying its competitor, you have valuable knowledge. But if everyone knows that, you aren't going to make as much in the market. In fantasy baseball, the more information you have, the more knowledge you have. If it is something the other guys in the league aren't looking at, it is very valuable currency. Let's take a look at some of the advanced pitching stats and examine how they can help you win your league this year.


By GabboT (http://www.flickr.com/photos/tonyshek/9234006918/) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

Batting Average on Balls in Play. This is also a stat that we use with hitters, only in the exact opposite way. BABIP takes into account what percentage of balls in play go for a hit. Everything from an at bat that ends in something other than a strikeout, a walk or a home run is included in this metric.

There is a strange little secret about baseball, which is that pitchers have relatively little control over what happens after the ball is hit. That depends on factors like quality of fielder, quality of hitter, and the pitcher's repertoire. Often, luck enters the equation too.  A great pitch can be nubbed over the third baseman's head, and a terrible pitch might be laced right at a defender.

There are some ways that a pitcher can control his BABIP - a power pitcher might induce weak contact. A ground ball pitcher can generate a lot of outs, all things being equal (we'll get to GB/FB in a minute). But for the most part, league-average BABIP indicates that everyone stays around a .300 in the long term.

This is important because for small sample sizes, a pitcher can have an incredibly high BABIP, which deflates their other numbers, or a low one, which can give a false impression of how well they are pitching. Either way, odds are they'll return to normal by regressing to the mean. Of course, this isn't a certainty, but it is reasonably likely. Take a guy like Max Scherzer. Awesome pitcher, but in 2013 his BABIP was an astonishing .259.  It's not impossible that he will do that again, but it is unlikely. Given other incidentals which aren't likely to repeat, you can look at BABIP and see that he might have been a little overvalued going into 2014. He ended up having a great year, but that's the general principle to apply for other pitchers.


FIP stands for Fielding Independent Pitching.  It is sort of the opposite of BABIP-- it is what the pitchers can control: home runs, strikeouts, walks, and hit by pitches. Home runs are obviously the worst thing a pitcher can give up, but strikeouts don't have as much value as you'd think (because there are some better outcomes). The best thing a pitcher can do is avoid giving up walks. The formula is complicated, and understanding it is unnecessary. Just know it does an amazing job of predicting a pitcher's future performance.

A pitcher could have a high ERA, but a low FIP, because the ERA is based on things that the pitcher can't always control. So if someone has a bad year by traditional stats, and you don't want to pick him up, check out his FIP. If it's low, then odds are the ERA is going to go down this year. The reverse is true as well - a FIP higher than ERA likely indicates an ERA rise is coming.

xFIP is a little less intuitive, because it takes into account how many home runs the pitcher should have allowed, based on league averages and his flyball rate. Sometimes the wind is blowing strange and knocks out an easy fly ball or keeps a bomb in the park, or the pitcher is in a terrible park, or the ball bounces off Jose Canseco's head (admittedly, the last one isn't a common thing). This stat is good, as you can guess that a pitcher will move toward the average, but you should take a look at their career home run numbers. If they are consistently high or low, chances are they are going to remain consistent. But if there is a year where his xFIP looks fluky, expect it to regress to its norm.


Home run to fly ball rate. This is kind of a neat one.  There is a league average to the rate of fly balls that turn into home runs. It varies a bit per season, but it is usually around 9-10%. There are a lot of factors that can influence an individual pitchers HR/FB rate, like ballpark size, wind and just bad luck. There are pitchers who have more control, but for the most part, someone who has a high HR/FB ratio will eventually even out and the home runs he allows will diminish. Obviously, if he's pitching in a bandbox or a hitter's park like US Cellular Field, then you have to take that into account.

So these are a few of the more advanced ways to see if a pitcher is going to be good or bad. You know Kershaw will be a stud, but these can help you take a look at middling pitchers, or guys who had a freak year one way or the other, and project whether or not it is a trend or a fluke. These stats can give you the inner track on why players under- or over perform, and if you can expect them to do it again. It gives you a better look at their actual value, which can help you hoist the trophy at year's end.


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