Lowest SLG by a DH, minimum 400 PA

I meant to post this yesterday but was attacked by some computer gremlins. Now that they're taken care of I want to turn attention to designated hitters who weren't good at hitting for power. A number of the guys on the lowest batting average and lowest on base percentage lists kept their jobs because they were capable of mashing the ball. By looking at the lowest slugging percentages, we should be able to find the designated hitters that were, essentially, slap hitters.

I'm going to make this a pretty long list, simply because giving the lowest thirty seasons for slugging percentage also gives you all the seasons of .400 or below. (EDIT: After reading the comments on the link Baseball Think Factory gave this entry, I realized I forgot to detail qualifiers for the list. The following are players who appeared in at least 75% of their games on the season as a designated hitter according to the B-R Play Index. Sorry for the confusion.):

1. Ken Singleton, 1984, .289
2. Carlos May, 1976, .333
3. Mitchell Page, 1979, .335
   
4. Alvin Davis, 1991, .335
5. Billy Williams, 1976, .339
6. Hank Aaron, 1975, .355
7. Tommy Davis, 1975, .357
8. George Bell, 1993, .363
9. Greg Luzinski, 1984, .364
10. Dave Parker, 1991, .365
11. Gates Brown, 1973, .366
12. Reggie Jefferson, 1993, .372
13. Tommy Davis, 1974, .377
14. Tony Oliva, 1975, .378
15. Ken Singleton, 1982, .381
16. Paul Molitor, 1998, .382
17. Edgar Martinez, 2004, .385
    
18. Jeff Burroughs, 1983, .387
19. Al Kaline, 1974, .389
20. Willie Horton, 1978, .389
21. Rico Carty, 1979, .390
22. Dwight Evans, 1990, .391
23. Harold Baines, 1992, .391
24. Tommy Davis, 1973, .391
25. Andre Thornton, 1986, .392
26. Don Baylor, 1987, .392
27. Jose Vidro, 2007, .394
28. Hal McRae, 1981, .396
29. George Brett, 1992, .397
30. Deron Johnson, 1973, .400

It's not altogether surprising so many of these seasons took place in the 1970's and 1980's. Slugging percentage league-wide was lower than fans today are accustomed to: in the first ten seasons of the DH, AL slugging percentage topped .400 all of three times. The AL slugging percentage hasn't dropped below .400 since 1992. That makes Seattle special in a dubious way; the Mariners are the only team to have a full-time DH since 2000 make the list, and they did it twice (Martinez in 2004 and Vidro in 2007)!

Regardless of the time he played in, Ken Singleton's all-time low mark is perversely impressive. It's hard to slug .289 and get 400 PA in a season, much less without playing impressive defense to back it up. Opening the search to all positions since 1973, only 144 players amassed 400+ PA in a season while slugging lower than .300. They were preponderantly shortstops, with the rest mainly second basemen and catchers. To show how rare it is, consider that 6,614 seasons of 400+ PA have been recorded since 1973. In either case, rare or not, the fact the second-lowest finisher had a .333 slugging percentage makes Singleton's mark stand out even more. I would say he holds one of the esoteric "unbreakable" records.