Following up on a point from last week – on the whole, home runs are down in both leagues this year, but far more dramatically in the AL, to the point where NL hitters are going yard more frequently than their AL counterparts for the first time in this decade. Of course, as the following chart shows, when you take out NL pitchers and AL DHs, the NL’s power output has been ahead all along, but is dramatically further ahead this season:
Year | AL-AB | AL-HR | AL-DH-AB | AL-DH-HR | NL-AB | NL-HR | NL-P-AB | NL-P-HR | AL-HR/600 | NL-HR/600 | AL-w/oDH | NL-w/oP |
---|---|---|---|---|---|---|---|---|---|---|---|---|
2007 | 73752 | 2120 | 7640 | 298 | 84208 | 2550 | 4505 | 26 | 17.2 | 18.2 | 16.5 | 19.0 |
2006 | 78497 | 2546 | 8035 | 392 | 88844 | 2840 | 4832 | 29 | 19.5 | 19.2 | 18.3 | 20.1 |
2005 | 78215 | 2437 | 8099 | 327 | 88120 | 2580 | 5025 | 18 | 18.7 | 17.6 | 18.1 | 18.5 |
2004 | 78731 | 2605 | 8146 | 328 | 88622 | 2846 | 4932 | 24 | 19.9 | 19.3 | 19.4 | 20.2 |
2003 | 78311 | 2499 | 8094 | 327 | 88426 | 2708 | 4981 | 29 | 19.1 | 18.4 | 18.6 | 19.3 |
2002 | 77788 | 2464 | 8159 | 316 | 87794 | 2595 | 4939 | 27 | 19.0 | 17.7 | 18.5 | 18.6 |
2001 | 78134 | 2506 | 8137 | 337 | 88100 | 2952 | 5007 | 26 | 19.2 | 20.1 | 18.6 | 21.1 |
2000 | 78547 | 2688 | 8178 | 352 | 88743 | 3005 | 5177 | 32 | 20.5 | 20.3 | 19.9 | 21.3 |
The last four columns are expressed in terms of home runs per 600 at bat. Of course, you could slice the numbers more finely if you had time, to take out the small number of AL pitcher and NL DH at bats and correct for Coors Field, but what’s interesting to me is the dramatic change in one season in the AL, much more dramatic than in the NL. I’ll leave you for now with the data but I may do a little more thinking about whether there is a plausible cause here beyond random variation.
Steroid use is down.
It is also possible that NL pitching is simply worse right now. It would be interesting to check the HR rate in interleague play. It is interesting how much of the VORP leaderboard by position is NL dominated on the hitting side (i.e. this is more than a HR effect). Look at shortstop – long the AL glory position, now dominated by Ramierez, Rollins, Reyes, and so on.