How to Quantify Lineup Protection in Baseball
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MLB lineup construction is a science that has been developing for over a century. The nuances of ordering hitters include alternating right-handed and left-handed batters to make it more difficult for opposing teams to exploit the platoon advantage, batting your least productive hitter 8th instead of 9th so that the number 9 hitter can act as a second leadoff hitter, and sometimes avoiding batting your best hitter 3rd since that spot is the most likely spot to come up with 2 outs and the bases empty.
In this analysis I’ll discuss lineup protection, that is, the impact that the hitter behind you has on the pitches you face. I’ll use the results of my lineup protection analysis to add another wrinkle to the lineup construction equation.
My dataset of lineup protectors is comprised of the 30 batters in the Statcast era with the highest single season weighted On-base Averages (wOBAs). I then found the batter who batted ahead of each protector in a plurality of at-bats that season. For each batter receiving protection, I calculated the strike % (percentage of pitches faced in the strike zone) and middle % (percentage of pitches faced down the middle of the plate) and compared those to the league average strike % and middle % for that season.
Table 1 lists my results.
Table 1: Lineup protection, ranked by Middle % Premium
Lineup protection, on average, increases the likelihood that the protected batter sees a strike on any given pitch by 0.25%. It also increases the chance the protected batter sees a pitch down the middle of the plate by 0.07%. Over the course of a season, a protected batter should expect to see 6 additional strikes and 2 additional pitches down the middle due to lineup protection.
Juan Soto has provided the best lineup protection, enabling Trea Turner to face an abundance of hittable pitches in both the 2020 and 2021 seasons. Furthermore, David Ortiz, Joey Votto, Freddie Freeman, and Mike Trout have also provided excellent lineup protection.
Some hitters, however, do not benefit from lineup protection nearly as much as others. The free-swinging Jose Altuve and Bo Bichette do not see a high number of hittable pitches even when protected by an elite hitter.
How Do the Results Translate to Lineup Construction?
Teams need to avoid wasting lineup protection on free swingers, and the Toronto Blue Jays have recently caught onto this. Last year, on Opening Day, the Blue Jays lineup featured George Springer, Bo Bichette, and Vladimir Guerrero Jr. batting 1st, 2nd, and 3rd. This year the Blue Jays Opening Day lineup features the same hitters at the top, but in a different order. They opted for Springer, Guerrero Jr., Bichette, knowing that Springer would benefit much more than Bichette from the protection that Guerrero Jr. offers.
