Hi Erik,
There are two reasons why what you're seeing won't match what's been
reported in an older article:
1. the data you're looking at on the DT cards is more recent than
what's in my spreadsheet, which was used for that article; I only
update once or twice a year, and Clay Davenport makes all kinds of
exceedingly minor tweaks in between that are too difficult to stay on
top of. New data will be forthcoming at the end of this month, with
some BIG changes in WARP that will render what you're looking at
somewhat outdated anyway ;-).
2. In the JAWS version of WARP, we assess a slight downward
adjustment to AL pitchers of the DH era so that they're not unfairly
aided relative to their NL and pre-DH counterparts by not having to
bat. This generally reduces a full season starter's line by 0.5 to
1.0 WARP relative to what you see on the cards.
Hope that helps. Look for updated JAWS stuff coming at the end of
this month. And thanks for reading.
Jay Jaffe
Author, Baseball Prospectus