ESPN has an extremely long article on the decline of batting average as the key baseball statistic and the concomitant decline of batting averages.
ESPN Staff Writer
Batting average — basehits divided by at-bats (with walks not being counted as either hits or at-bats) was the premiere baseball statistic until the late 20th Century. The highest batting average player for a season is known as the Batting Champion.
The article uses the story of how Mickey Mantle sadly wound up, during the Pitcher’s Era of the 1960s, with less than a .300 average for his career, which caused him to be looked upon as overrated in the 1970s. (Modern analysis, however, finds the Mick to be just as great as fans thought at the time. Sabermetricians like to believe that they are digging up new knowledge about the past, but they mostly come up with findings in line with what the paying customers of baseball had thought at the time: e.g., Babe Ruth, Lou Gehrig, Ted Williams, and Mickey Mantle were great hitters, just like fans said.)
Similarly, Albert Pujols, who hit .328 from 2001 to 2010, will likely fall below a career .300 average this season as the new computer-driven shift defenses turn his line drives into outs.
Heck, the unworldly Mike Trout only has a career average of .306 and it seems likely that he will enter the Hall of Fame around 2040 with a career average around, say, .285 or .290.
On the other hand, I would like to offer a defense of batting average as a useful statistic. It is criticized as a poor indicator of how much a batter is helping his team win because it ignores getting on base via a walk and it doesn’t give credit for extra base hits. So, batting champions can be less valuable than players with more walks and homers.
Four time batting champion Bill Madlock, for example, was a fine hitter with a .305 career batting average, but he didn’t bring all that much other than his batting average to the table. The sabermetricians love to point out that, say, Bobby Grich was a better all-around player even if his batting average (.266) was considerably lower. Interestingly, despite Madlock’s gaudy batting average, he never finished above 6th in the MVP voting and only got 4.5% the one time he was allowed on a Hall of Fame ballot, so it’s not as if pre-sabermetrics sportswriters were wholly deluded by the glamor of batting average.
So, batting average isn’t that useful for comparing between hitters. What it is useful for, however, is comparing a player to himself. Specifically, a high batting average relative to his career correlates with a player playing closer to his potential. Batting average is a helpful measure for determining if a player is having a hot streak or a slump.
For example, Cody Bellinger of the Dodgers entered tonight’s game hitting .401, which is impressive for a low batting average season. And, indeed, he is by all accounts a much improved hitter over his first two seasons when he hit in the .260s. Even though he hit 38 homers in his rookie year of 2017, by the World Series, the Astros pitchers had figured out how to dismantle his long swing and he only hit .143 with 17 strikeouts in 29 plate appearances.
Apparently over the 2018-2019 winter he figured out how to patch the holes in his swing, and this season he has a league leading 61 hits to only 25 strikeouts.
In contrast, last season Texas Rangers Joey “Three True Outcomes” Gallo struck out 207 times and had only 103 hits, or fewer than half as many hits as strikeouts as he batted .206 but with 40 homers.
One value of the batting average is that it provides a bigger sample size, whereas measures heavily weighted by home runs can be fluky over short time spans, since homers are relatively rare.
You can see this even with all time great power hitters. For example, in Babe Ruth’s 1923 season, his homer total dipped to only 41 compared to 59 in 1921. But he batted a career high .393. And sure enough, modern sabermetrics usually points to 1923 as his career peak.
Ted Williams hit .406 at age 22 in 1941 and .388 at 38 in 1957, his two highest average seasons, and, indeed, modern analysis points to those as his best seasons at the plate.
So, while batting averages are of little use for comparing players, they are a good measure for comparing the player to himself.