Using Sabermetrics For Fantasy Baseball Part 4 - Batted Ball Distribution (Hitters)

Fly balls can turn into home runs. Ground balls never do. It would seem as though fantasy owners want their batters to hit nothing but flies, yet this is not the case.

Why would this be? The answer, of course, comes down to batted ball distribution and the manner in which batters make contact.

In this article, we'll continue evaluating the most effective ways to use sabermetrics to get an edge in your fantasy baseball leagues.

How to Interpret Batted Ball Distribution

Let's first look at how all major leaguers fared on each of the major types of batted ball in 2018. Grounders generated a BABIP of .236. Flies were not as productive, posting a .117 figure. This makes sense, as popups almost never fall in, cans of corns to the outfield are only slightly better, and homers are considered out of play and do not count toward BABIP. Line drives turned into base hits far more frequently than either of the others, posting a .672 BABIP. The difference between liners and anything else is startling. Batters want line drives.

Matt Kemp's resurgence provided a good illustration of what a few extra liners can do in 2018. He posted a .290/.338/.481 triple slash line thanks in part to a 26.8% line drive rate. Kemp was an afterthought in real and fantasy baseball terms heading into 2018 but ended up surprisingly productive in both areas.

A player's LD% tends to bounce around the league average with random spikes and drops, none of which offer much predictive value moving forward. Kemp has a 22.5% LD% over his career, so luck was almost certainly the primary driver of his 2018. When BABIP is driven by luck, LD% is usually why.

This is not to suggest that no one consistently posts above-average LD% rates. For example, Joey Votto's career .352 BABIP is driven by his career 25.8% LD%. Considering the length of his career, it would be stupid to suggest that Votto has enjoyed a lucky decade-plus. Therefore, we give credit to Votto for being a plus-BABIP guy due to a LD% skill, just like we give Mookie Betts BABIP credit for his blinding speed. This distinction has to be earned over numerous full seasons, however. Most LD% surges are more fluky Matt Kemp than sustainable Joey Votto.

Unlike LD%, both GB% and FB% are stickier--a player with an elevated rate in one is likely to repeat a similar rate moving forward. By BABIP alone, grounders are better. However, this changes significantly if slugging percentage is considered. In 2018, grounders offered a slugging percentage of .258, only slightly higher than the .236 BABIP they posted. Flies had a .690 slugging percentage, easily offsetting the lower BABIP for most fantasy players. Sluggers like Khris Davis who lift the ball at an exceptional rate have a built-in slugging advantage because of their batted ball profiles.

The ideal batted ball mix, therefore, varies with the player. Elite speedsters like Billy Hamilton want more grounders than flies, as his career 3.4% HR/FB despite a favorable home park is never producing a lot of homers anyway. Sluggers like Albert Pujols want fly balls, especially since the shift and his lack of speed prevent him from realizing the larger BABIPs associated with grounders anyway. Fantasy owners usually prefer players with power and speed potential to have a higher FB%, as the extra power is more beneficial than a few extra times on base.

Incidentally, line drives averaged a ridiculous .900 slugging percentage to go with the .672 BABIP in 2018, so they are still the batted ball of choice.

Conclusion

To conclude, line drives are by far the most productive result for hitters. BABIP's luck-driven fluctuations are driven by LD%, a largely random stat. GB% and FB% are more predictive, and which one is favored depends on the hitter in question. Grounders offer a higher BABIP, but almost zero power. Flies result in base hits less often, but generate much more power when they do. The intricacies of BABIP could be a never-ending topic, but the information provided so far is generally enough for fantasy purposes. Next up, we'll look at the other major component of a player's batting average: plate discipline.

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