Diamondbacks’ Lineup Protection

Did lineup protection positively impact the Diamondbacks in 2020?

Does the Diamondback batting order have spots with lineup protection? Lineup protection means that the next batter is a power hitter who is respected by the other team’s pitcher. In theory, because of that next batter the pitcher gives the current batter pitches that are easier to hit.

If I was a pitcher, the Diamondback power batters who would concern me most are Kole Calhoun and Christian Walker. This AZ SnakePit article concludes that those two, plus Seth Beer are the team’s power hitters.

Before we look at the impact of those power hitters, let’s briefly look at the wide range of viewpoints on whether lineup protection exists league-wide.

One view is that lineup protection does not exist. Tom Tango wrote that the only impact of lineup protection is to increase the ratio of walks to non-walks. There is no impact on hitter performance if the batter is not walked. His article is interesting.

Another type of view is something else is more important. More important is to avoid stacking lefties and stacking righties (Joe Girardi & Kevin Cash). More important is to stick to the game plan (CC Sabathia). More important are the pitcher-batter matchups and historical results for those matchups (Mark Teixeira & Tim Hudson). More important to the pitcher is to avoid getting behind in the count.

“Every hitter is dangerous when he’s ahead.” — Kevin Jepsen

Another type of view is that the importance of lineup protection depends on other factors. Three of those factors are:

• Is the batter experienced or a rookie? The impact of lineup protection depends on the batter’s experience. More experience allows the batter to take advantage of the situation.
• Are runners on base? Runners on base usually demand that the pitcher focus on getting the current batter out, regardless of whether he is protected (Kevin Jepsen).
• Is it early or late in the game? Early in the game there are a lot of innings remaining to be played. The theory is that late in the game, especially if the score is close, every run can impact who wins. Therefore in that situation, it is best to take into account whether the batter is protected (Adam Warren).

Let’s look at the Diamondbacks data and make our own conclusion.

For batters who were protected (immediately in front of either Kole Calhoun or Christian Walker), let’s look at their HRs/AB and RBIs/AB in those games and compare those statistics to games when they were non-protected. In addition, when batters were protected, lets look at the ratio of RBIs (successes) to runners left-on-base (LOBs) (non-successes). Shaded in green means the protected batter performed better, while shaded in red means protected batter performed worse.

2020. Excludes batters with <10 protected ABs. Assumed ninth batter is always non-protected. Data from MLB Gameday & Baseball Reference.

Why did I circle the ratio of RBIs to LOBs for David Peralta and Josh VanMeter? Those two batters had more success when they were protected. Their success suggests they should bat with protection.

Ketel Marte had the most at-bats (88) in protected games. Unlike Marte and Escobar who had protected games throughout the season, Peralta’s protected games happened in 3 weeks of August, and VanMeters’ protected games happened in 2 weeks of September. Perhaps those two periods were lineup experiments. If so, they appear very successful. The cause of that success is not obvious because of the question, “What else might have been different in those two periods?”

In summary, lineup protection may have existed for two batters. To make a more definitive conclusion, this question needs to be revisited in 2021.