Another Sign Batting Average Is Becoming Obsolete

One of the great batting lines of the first half was Yasmani Grandal’s .189/.388/.436 slash. Unfortunately, as has been the case for many a hitter on the White Sox, his return to action in ‘21 is in doubt after he underwent surgery to repair a knee ligament. I won’t wax poetic on Grandal; Devan Fink did a great job covering his early-season batting line. But it’s becoming more common to see a hitter with an average that starts with a “1” these days. The common reference to a batting average under .200 is the “Mendoza Line,” which our Ashley MacLennon made a strong case for ditching as a reference earlier this season. I, on the other hand, am going to make the case for why it’s become irrelevant.

Batting average, the prevailing measure of a hitter’s success for most of baseball’s existence, has faded into the background, yet the rate at which a hitter successfully reaches base via a hit is still usually the first statistic reported. Grandal’s batting average is not good, but the selection of .200 as a cutoff point is arbitrary; after all, a batting average of .214 is also not good. What most baseball fans understand now is that because all base hits are not equal in value, batting average is limited in what it says about a hitter. But there is a stigma attached to a poor batting average, which is probably why the Mendoza Line has stuck.

Let’s rewind to last year’s shortened campaign. There was a lot of speculation going into a 60-game season as to whether or not a player would be able to hit .400. That didn’t happen, though Charlie Blackmon was hitting .500 after a couple weeks. We did end up with a handful of qualified hitters with an average below .200 — seven such, to be exact:

This is by far the highest number of qualified hitters with a batting average below .200 for a single season. It is totally a product of the short season, though. None of the hitters on the list above are contact hitters, but their true bat-to-ball skills are probably better than what they showed in ‘20. When the sample is small, there is a greater chance that you get some outliers in your results.

So if we’re filtering out hitters by the definition of qualified (at least 3.1 plate appearances per game), this distinction for the 2020 season doesn’t say a whole lot. That does seem like a lot of hitters who are getting innings every day, though, despite really poor contact. If we reduce the minimum number of plate appearances to 100, we can make a more appropriate comparison to previous seasons.

A total of 38 players with over 100 plate appearances during the 2020 season had averages at or below .200. So far this season, that number is 50, though as the season continues and players with a history of better contact than they’ve shown this season so far (e.g. Cody Bellinger, Ian Happ) get more plate appearances, that list should get shorter.

As you can see from the chart above, front offices and managers seem to have become more comfortable with sub-.200 hitters in recent years. These numbers fluctuate a bit from season to season, but at a macro level, there is a recent trend towards more hitters who bat below .200. That number has doubled in the last decade; compare it to the 1980–2010 period, when it was relatively stable.

This season started off slow for hitters — historically slow. That makes sense; pitchers are throwing harder, and teams are getting better at leveraging analytics to implement shifts and take away hits. But contact is not valued as much as it was in prior seasons. There is a good chance that Eugenio Suárez, Paul DeJong, and Grandal (were he not injured) end the season with a batting average below .200 with their teams still satisfied with the overall results. As you can see from the list of 2020 players under .200, with enough power and walks, it’s not unreasonable to expect that a sub-.200 hitter could provide value; Muncy, Olson, and Tsutsugo were all near league average in wRC+.

How is this possible? As long as any vacated hits are mostly singles, there is little harm done. Take Olson for example. Despite hitting just .195 last season, he hit 5.7 home runs per 100 plate appearances, which is slightly below his career average. His walk rate was also 13.9%, a small bump over his career average of 11.0%. It was still his worst hitting performance in the big leagues, but he gave the A’s value at the plate despite the poor batting average.

Grandal is a more extreme case of this:

Most of our readers probably look to wOBA and wRC+ as the primary aggregate hitting statistic to evaluate a hitter’s performance. These statistics appropriately weight the outcome of a plate appearance, rewarding hitters for extra-base hits. The increased propensity of sub-.200 hitters is just a natural consequence of an increased appetite for power hitting. The rate of singles hit per plate appearance has gradually gone down (from 17.1% in 1980 to 13.6% in ’21), but home runs have gone up (1.9% versus 3.2%). These rates both have a linear relationship with the number of sub-.200 hitters (plotted below).

To translate those rate changes, that’s a loss of 3.5 singles per 100 plate appearances in exchange for a gain of 1.3 home runs per 100 plate appearances — a net gain of 1.7 total bases per 100 plate appearances.

Even though it’s becoming obsolete, batting average still leads the slash line and gets printed on the back of baseball cards. But in today’s game, it might make more sense to pay attention to a minimum home run threshold. The number of hitters with a goose egg in the home run column is certainly in decline: six hitters in the last full season (2019) with at least 100 plate appearances, compared to 36 from the 1980 season. (Watch out David Fletcher, this one could get named after you.)

MLB is making efforts to bring more contact to the game; if it’s successful, this trend may begin to reverse. But until that happens, we will continue to see power trump contact. Embrace the slash line that starts with a 1; it’s here to stay (at least for a while).