When Terry hit .401 in 1930, the National League average was .303, and three other men topped .380.

This is not that type of year. The AL batting average entering Saturday was .264, the NL average even lower.

He's going to have limited defensive responsibilities.

Hornsby and Lajoie are the only middle infielders to hit .400. Hornsby was notoriously indifferent to defense, going so far as to refuse to catch pop-ups (that would require him to look into the sun and might damage his eyes.) Lajoie played in a time when double plays were rare and defense at second was less important.

The other nine .400 seasons came from first basemen and outfielders. And those outfielders were not known as good defensive players either.

Mauer, of course, catches. He has major defensive chores and performs them well. He doesn’t have the luxury of focusing on his hitting.

He’s going to play in a hitter’s park.

The most likely venues: Coors Field (Denver), Fenway Park (Boston), Wrigley Field (Chicago).

The Metrodome skews toward pitchers, although that’s because it chokes off home runs. It’s a pretty good park for hitting for average, although not like those three.

He’s probably going to come very close to the minimum standard of 501 plate appearances, and will further cut down on official at-bats by drawing walks.

This assertion is not based on the historical record so much as logic. It’s got to be easier to get 200 hits in 500 at-bats than it is to get 240 hits in 600 at-bats. The shorter the season, the more likely it is to get an outlier average.

Mauer has this on his side. His 2009 season has been shortened by a full month by his back injury. Indeed, he remains short of qualifying, although he’s closing the gap rapidly.

Edward Thoma is a Free Press staff writer. He is at 344-6377 or at ethoma@mankatofreepress.com. He also has a baseball blog at www.mankatofreepress.com/ethomabaseball