Hitters 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, UBR, O-Swing, Z-Swing, Line Drive %.


Advanced statistics are not new. Though as recently as 10 years ago they were the subject of much derision among sportswriters and broadcasters, all but the most hidebound and dusty now acknowledge their existence, with most embracing them at least to some extent. Even Hawk Harrelson-- he of "The Will to Win"-- accepts and uses On-Base Percentage during ChiSox broadcasts. At this stage, of course, it seems kind of ridiculous that On-Base Percentage or Slugging Percentage are considered advanced stats: they are stats kept in many of our fantasy baseball leagues, and nearly every baseball fan is conversant with them.

But that's exactly the point. When these stats were new, the few people who could understand them had a decided edge in analysis. But now that they are common, they aren't as good at getting a leg up on the competition. So we're going to look at some other stats-- some relatively common, some more on the fringe (at least depending on whom you're talking to)-- that can help you get the inside edge in your fantasy baseball league this year.


Advanced Stats for Fantasy Baseball

A quick note before we proceed: these are all projection stats. Baseball is a strange and unpredictable game, and wonderful because of that. Odd things can happen, distanced from any analysis. But these advanced stats should give you a good idea of how things should go in the future.



This is a stat that is on the verge of mainstream acceptance, but until it gets there, it is one of the key indicators you can use to get the edge on other people in your league.  It stands for "batting average on balls in play," and is pronounced "BAH-bip". What it measures is a batter's average on balls that can potentially make an out. This excludes walks, home runs, and strikeouts-- the three outcomes that the defense has nothing to do with. While players generally have a 30% average to get a hit on balls in play, the numbers can swing wildly for a week, a month or even a season, and also vary based on hitter's skills.

And you know this, instinctively. How many times have you heard an announcer say "Hit well, but bad luck! Right to a fielder!" All the time, right? Because here is the thing: most hitters cannot control exactly where the ball goes, and no one can do it consistently. What they can do is control how hard they hit the ball, and how frequently they make solid contact (more on this later).

We see BAPIP flukes all the time, and you can use this to your advantage. Say you've drafted 2015 golden boy Josh Donaldson, who should be about a .265 hitter. After three weeks, he's hitting .387, and ESPN is going nuts about how he's taking his game to a new level. Now, he's a great player, but you look, and see his BABIP is well over .400.  You can expect that BA to drop significantly as the BABIP normalizes closer to Donaldson's historical norm of .290. But your buddy doesn't know that, and so Donaldson's trade value is worth way more than it should be. You strike fast, and are able to turn a hot start into Anthony Rizzo and Anthony Rendon, who maybe struggled out of the gate. You'll smile smugly when Donaldson bats .220 in May.


Line-Drive / Ground Ball / Fly Ball Percentage

Pretty straightforward. What percentage of a batter's balls in play are line-drives, fly balls, or ground balls? This is usually a stat that describes why a player is good, rather than predicting that he will be good. Hitting it in the air tends to produce the most outs, but also home runs for the powerful guys. Ground balls cause a slightly lower % of outs than fly balls, on average (speedy guys like Dee Gordon are an exception), and line-drive hitters tend to have the most fluctuation due to luck, but will usually have the highest batting averages.

While this isn't a stat generally used for predictive purposes, you can use it if you see what appears to be a flukish start for a player on your squad or on someone else's.  Imagine a buddy has Joey Votto, and after a month he has ten home runs. You see that Votto's FB% is at a low 28%, as opposed to the 40% level of most power hitters. One of your league mates might assume Votto has his power stroke back, but it is more likely he had some great luck in seeing a huge percentage of those fly balls leave the park.

Votto will soon regress to his career norm HR/FB rate, and with the low number of fly balls he hits in the first place, the power that came back in a flash will fade away just as quickly. By paying attention to career norms and small sample sizes, you have more information with which to analyze a players potential future performance. If your friend isn't looking closely at the numbers, he might be willing to make a trade and overpay for Votto.



This is a fun one, especially for people who say you can't quantify things like smart base-running. Well, this attempts to do just that.  Different places have different methods of calculating it, but UBR seems to me to be the most comprehensive. It is important to note that it doesn't account for base-stealing, which is separate category. It takes into account things like properly tagging up, advancing from second to third on a grounder to short, taking an extra base (or getting caught while trying to do so).  It is properly complicated-- I'm certainly glad someone else charts this and does the math-- but it does give you an insight into a player's game, especially if he has been traded or his team has been reshaped around him.

A high UBR shows you that the player does an excellent and often team-independent job of getting in position to score.  So if your player has scored a lot of runs, but you are worried how a trade might affect that, take a look at UBR. Obviously, runs scored are always team-dependent, but getting yourself in position to score is often a matter of individual skill. A good UBR player won't drop off the map because he has a lesser batter hitting behind him, whereas a bad one will struggle more.


O-Swing, Z-Swing & Others

While these might sound like the names of mediocre rappers performing "hip" life lessons at a middle-school symposium on strangers, they are actually fascinating ways to measure a batter's plate discipline.

O-Swing is the percentage of pitches outside the strike zone a batter swings at; z-swing the percentage inside the zone.  You also have O- and Z-contact, as well as a few others to help you determine how frequently a hitter makes contact on pitches outside and inside the zone.  You want lower in the O and higher in the Z in terms of swinging.  There are exceptions, like Vlad Guerrero swinging at an insane 40% of pitches out of the zone in his career-- but Vlad was insanely great, and he connected on nearly 70% of those. Vlad is the exception.

This is a great way to track someone's progress as a hitter, to see if he is maturing, or if he is always going to be swinging at everything. When analyzing a player's career, see if he is improving in terms of plate discipline. Interestingly, some guys like Adam Dunn have great plate discipline (which is why he walks a ton) and huge strikeouts for the same reason: he never  swings at pitches outside of the zone, and too often keeps his bat on his shoulder on pitches that are close, putting him in the hole on corner pitches. Use these stats to judge a player's mental development before drafting. Also, players with higher Z-contact rates are less prone to wild batting average swings. They more frequently make contact with quality pitches to hit, giving them a better chance to maintain a solid average.


So, that's just a few of many amazing new hitting stats that not only have reflective, but also predictive possibilities. Even if your league still holds batting average sacred and feels that runs scored is the one true measurement of a hitter, you can see the factors that go into these stats, and you can use that knowledge to take hold of your league. Doing so will prove that you have The Will To Win.