While FIP is a useful tool to predict a pitcher's future ERA performance, fantasy owners should remember that ERA, not FIP, is what really matters in most formats. This means that we are interested in the "luck" that separates the two statistics. Some of this is unpredictable, but we can and should predict some of what goes into a pitcher's bottom line.

The first variable is location, or where a given pitcher pitches. While most fantasy owners are familiar with certain ballparks allowing more or less homers than others, BABIP is an under appreciated component of ballpark factors. Altitude, infield conditions, foul territory, batter's eye and the size of the stadium can all influence how a ballpark plays beyond just home runs.

For example, the Colorado Rockies managed a .346 BABIP at home last season against a road BABIP of .276. Likewise, they posted a .361 figure at home against a .285 mark on the road in 2014, with similar differences in every other season. Players tend to perform a little better at home, but Colorado's splits seem indicative of more than that.

Coors Field is a gigantic ballpark, offering plenty of real estate for balls to find grass. Pitchers claim that breaking balls behave differently due to the elevation of the Mile High City, removing some of their weapons. Fatigue may set in faster for the same reason. The introduction of the humidor has decreased the ballpark's HR rates compared to the complete bandbox it was at the height of the Steroid Era, but it still consistently posts the highest BABIP in baseball. For that reason, and not dingers, fantasy owners should be leery of selecting Colorado hurlers. Colorado is the most extreme example, but every stadium has some quirk that makes it unique.

With location out of the way, we can look at other factors. When calculating BABIP for hitters, we assume a neutral defense because they figure to see a balance of poor and skilled defenders as they travel around the league. This is not true for pitchers, as they always pitch in front of their own club's defenders. A team with Andrelton Simmons and his 25 Defensive Runs Saved (DRS) figures to provide better defense to its pitchers than a team that lacks a platinum glover. DRS is a counting stat like HR or RBI that measures how strong a defender a particular player is, with zero corresponding to an average defender and negative numbers possible for weak gloves. A better defense helps pitchers outperform their FIP.

BABIP is also partially determined by a pitcher's style. An extreme groundball pitcher may have a higher BABIP against because grounders have higher BABIPs than flyballs (.236 to .129 in 2015.) This stylistic difference also changes how much a given pitcher will benefit from (or be hindered by) a particular defender on his team. For instance, a groundball pitcher would love to pitch in front of Simmons, while a flyball specialist would benefit more from an elite OFer instead.

Houston's Dallas Keuchel qualified as a clear groundball specialist in 2015, posting a 61.7% GB%. Despite this, he managed a below average BABIP of .269 last season, inspiring some to call for significant regression in 2016. A simple GB vs. FB comparison oversimplifies the matter, however. Keuchel posted an 18.7% LD% in 2015, and has posted a below average mark in each season of his MLB career. As you may remember from an earlier article, line drives had a BABIP of .678 in 2015, easily dwarfing the other two types of batted ball. Suppressing liners is an effective and apparently sustainable way for Keuchel to suppress his overall BABIP. Likewise, 12% of the flies he did generate were of the infield or popup variety, a few ticks better than the 9.5% league average rate. Infield popups are generally harmless, so getting them reliably also reduces a pitcher's BABIP.

Every pitcher allows a few hits, and the sequencing of these events may also cause a difference between a pitcher's FIP and ERA. Allowing three base hits over three innings is probably harmless, while allowing three hits in one inning and then nothing in the next two frames likely puts a run on the board. Sequencing luck is measured by strand rate, or LOB%, and research shows that it is largely an unstable, luck-driven stat. In 2015, the league average LOB% was 72.9%, with higher numbers generally forecasting a higher ERA moving forward. Elite strikeout guys tend to be the best at getting the K "when they need it," and as such may sustain slightly elevated strand rates.

To conclude, a pitcher's BABIP includes some unknown variables but also includes some predictable inputs. The pitcher's home stadium influences more than just his HR/FB rate. The quality of his defense can help or hurt him. Sequencing does not affect BABIP necessarily, but can impact a pitcher's ERA substantially. A given pitcher's style, as a groundball or flyball specialist, may also impact his performance. BABIP is just the beginning of that relationship, which will be explored further in Part 8.

MLB & Fantasy Baseball Chat Room