Baseball by the numbers: Adam Dunn shows his value in secondary average
BY JOHN GROCHOWSKI For Sun-Times Media August 20, 2012 8:52PM
Updated: September 22, 2012 6:24AM
Baseball fans long have used batting average as a prime measure of a good hitter. The image of a .300 hitter as a star and a .250 hitter as a
mediocrity is firmly entrenched.
But batting averages don’t measure times on base through walks or hit batsmen. They don’t measure the extra bases taken on doubles, triples or home runs. In batting average, a single counts the same as a homer, even though the homer guarantees at least one run and drives in everyone on base ahead of it.
That’s why the sabermetrically inclined prefer OPS or, better yet, Bill James’ runs created per 27 outs, David Smyth’s base runs or other sophisticated measures of a hitter’s value.
What if you wanted to separate out all bases generated by a hitter that aren’t included in batting average and give that its own stat? That’s what secondary average, another James formula, does.
Secondary average, which you can find on the sabermetric stats pages at ESPN.com, adds walks, doubles, two times triples, three times homers and stolen bases, then subtracts times caught stealing. That total then is divided by at-bats to yield a percentage.
Why three times homers instead of four to account for all bases? Because homers are included once in batting average, and in secondary average we’re interested only in those bases not accounted for in batting average.
Through Sunday, the major-league leader in secondary average was the White Sox’ Adam Dunn at .487, 11 points ahead of the Blue Jays’ Jose Bautista. That’s not a surprise. Dunn isn’t the best hitter in the league, but he’s a valuable one. And his value is tied up in walks and homers.
Beyond secondary average, Dunn is on his way to a historic season. He leads the American League in all ‘‘three true outcomes,’’ hitter-against-pitcher results not affected by defense: homers, walks and strikeouts. If that holds up, he’d be the first ‘‘Triple Crown’’ winner in those categories in the AL since Mickey Mantle in 1958.
On the North Side, there is no one with Dunn’s unusual skill set of power, walks and very low batting average. The Cubs’ leader in secondary average is Alfonso Soriano at .307. That ranks 23rd in the National League, 120 points behind the Brewers’ Ryan Braun, who leads the league.
What if you looked at the hitters who do the least outside of batting average? The lowest secondary average among major-league regulars is .131 by the Rangers’ Michael Young, a shade lower than the .138 by the White Sox’ Alexei Ramirez. Another near the bottom is the Yankees’ Ichiro Suzuki, who always has had an above-average share of his offensive value tied up in batting average. He’s 134th among 142 qualifiers at .176.
That doesn’t mean a hitter with a low secondary average can’t be valuable. He can, provided the batting average is high enough. And a hitter with a low batting average can be valuable with a high enough secondary average. Each is just a piece of the offensive puzzle.