A peek at peaks

The average major league hitter peaks by age 29, according to most baseball statistical analysts. That means the statistical likelihood, with Joe Mauer turning 30 today, is that he's on the cusp of a personal decline. A 2010 study by J.C. Bradbury in Baseball Prospectus researched the age at which good players peak in several offensive statistical categories. Bradbury analyzed only players who played at least 10 seasons with a minimum of 5,000 career appearances; he looked at all such players between 1921 and 2006. The results:

Category Peak age

On-base percentage30.0

Slugging28.6

Batting average.28.4

Walk rate32.3

Doubles, triples rate28.3

Home run rate29.9

Overall29.4