RADIO
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 way to use sabermetrics to get an edge in your fantasy baseball leagues.
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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 2017. Grounders generated a BABIP of .241. Flies were not as productive, posting a .130 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 .682 BABIP. The difference between liners and anything else is startling. Batters want line drives.
Oakland Athletic Jed Lowrie provided a good illustration of what a few extra liners can do in 2017. He posted a .277/.360/.448 triple slash line last year against a career line of .261/.332/.408. The reason was a 27.1% LD%, nearly seven full percentage points better than the league average mark of 20.3%. That may not seem like much, but look at the massive difference between liners and anything else above. That 7% was enough to make a mediocre hitter fantasy relevant.
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. Lowrie has a 22.8% LD% over a career lasting 3,812 PAs, so luck was almost certainly the primary driver of his 2017. 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 .354 BABIP is driven by his career 25.2% LD%. Considering the length of his career, it would be stupid to suggest that Votto has enjoyed a lucky decade. Therefore, we give credit to Votto for being a plus-BABIP guy due to a LD% skill, just like we give Jose Altuve BABIP credit for his blinding speed. This distinction has to be earned over numerous full seasons, however. Most LD% surges are more fluky Jed Lowrie 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 2017, grounders offered a slugging percentage of .262, only slightly higher than the .241 BABIP they posted. Flies had a .751 slugging percentage, easily offsetting the lower BABIP for most fantasy players. This is why Giancarlo Stanton is so good, as his 40.4% career FB% is much higher than the 2017 average of 35.5%. He hits with much more power as a result.
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. 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 .901 slugging percentage to go with the .682 BABIP in 2017, 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.
