Lowest Batting Average for a League RBI Leader

For a little while now I've been meaning to put together a post with records to watch for in the second half of the season. I haven't actually sat down and looked for anything yet for a number of reasons. Luckily, a comment was posted here yesterday by someone with the intriguing nom de plume of Death:

Ryan Howard is on pace to lead the NL in RBIs with an abysmal .220 batting average. Do you have any idea what the record is for the lowest batting average while leading his league in RBIs for the season? Thanks.

I thought that question was pretty interesting, so I decided to look it up. Howard is now hitting a robust .223 (75 for 337) and his 76 RBI still leads the National League. Below I've listed the fifteen lowest batting averages by a league RBI leader for both the American and National leagues since 1901. I've expanded tied (to three decimal places) batting averages to four decimal places to make the actual order clearer.

Lowest Batting Average by an NL RBI Leader, 1901-2007

1. Jim Nealon, 1906 PIT, .255
2. Howard Johnson, 1991 NYM, .259
3. Andruw Jones, 2005 ATL, .263
4. George Kelly, 1920 NYG, .266
5. Bill Dahlen, 1904 NYG, .268
6. Johnny Bench, 1972 CIN, .2695
   
7. Hank Sauer, 1952 CHC, .2699
8. Darren Daulton, 1992 PHI, .2701
9. Vinny Castilla, 2004 COL, .271
10. Mike Schmidt, 1984 PHI, .2765
11. Matt Williams, 1990 SFG, .2772
12. Mark McGwire, 1999 STL, .278
13. Hank Aaron, 1966 ATL, .279
14. Johnny Bench, 1974 CIN, .2802
15. Sam Mertes, 1903 NYG, .2805
    

Lowest Batting Average by an AL RBI Leader, 1901-2007

1. Harmon Killebrew, 1962 MIN, .243
2. Cecil Fielder, 1992 DET, .244
3. Harmon Killebrew, 1971 MIN, .254
4. Lee May, 1976 BAL, .258
5. Cecil Fielder, 1991 DET, .2612
   
6. Dick Stuart, 1963 BOS, .2614
7. Del Pratt, 1916 SLB, .267
8. Tony Armas, 1984 BOS, .2676
9. Gus Zernial, 1951 CHW/PHA, .2680
10. Roger Maris, 1961 NYY, .269
11. Rudy York, 1943 DET, .271
12. Larry Doby, 1954 CLE, .272
13. Ken Harrelson, 1968 BOS, .2748
14. Jackie Jensen, 1955 BOS, .2753
15. Harmon Killebrew, 1969 MIN, .276
    

So if Ryan Howard manages to keep on top of the RBI leaderboard without improving his batting average, he'll set a record. His batting average looks as though it will see some improvement however: his BABIP sits at .268 while his line drive percentage of 20.3% suggest his BABIP should be about fifty points higher. Once those hits start falling in, his batting average will improve. Going half a season with such a poor batting average, however, means he would have to have an amazing second half to avoid appearing on the above NL list following the season if he keeps driving in runners.