This article on the lack of regular designated hitters bothered me:

Being the DH is Ortiz’s full-time job. Except when the Red Sox play an Interleague game on the road, the only glove he needs is a batting glove. Which is how the role was envisioned in the beginning. Hal McRae. Willie Horton. Don Baylor. Jim Rice. Rusty Staub. Harmon Killebrew. Rico Carty. More recently, Frank Thomas and Edgar Martinez.

But the designated hitter is evolving. As Bill Chuck of Billy-Ball.com pointed out recently, fewer and fewer teams have a dedicated DH anymore. Going into play Monday, only Kansas City’s Billy Butler and Ortiz had played as many as 80 games there.

In the meantime, nine of the 14 AL teams have used 10 or more different hitters as their DH.

There are, it seems, two major reasons for this trend. One is that pure sluggers have become harder to find. The other is that managers recognize the value to using the spot to give their regulars a rest while keeping their bat in the lineup.

I don’t think the long term data agrees with this view. The graphs here show the average number of designated hitters starting for a team each year since 1974, and the number of designated hitters with 80 starts per 14 teams (this puts things on the same scale for the early years of the DH, when there were 12 teams in the AL). In other words, it shows how many players per team the league uses as designated hitters, and how many of them were regulars. As you can see, the first number tends to stay between 8 and 10 and fluctuates. There’s no clear trend. The latter number, at least 80 starts at designated hitter, has gone up in recent years. In the last three seasons, the number of DHs getting at least 80 starts were 12, 9, and 10. So far there are only two in the AL with 80 starts at the position, but we’ll see how it plays out. This may just be an off year, as opposed to a trend.