Baseball Graphs is dedicated to the better use and communication of baseball statistics. Below, you'll find excerpts from, and links to, some of the best baseball writers on the Internet. Follow the links above to read my own intermittent attempts at wisdom (the Baseball Graphs blog), and the heart of this site, historical graphs of every season dating back to 1900.
There are also two special sections you might want to check out. One is the graphical review of the 2003 season, which informed our work at The Hardball Times. The other is the Batted Balls Library, which includes a unique look at batters and pitchers from 2002 through 2005.
While commenting on Chris Dial’s Baseball Primer article on Defense Efficiency Ratio, I came up with a new, half-baked idea. What if I looked at the data I ran for the baseball history graphs, and compared each team’s DER to the league DER at the time?
So I did. I call this stat DER+. It’s similar to OPS+ and ERA+, which are listed at Baseball Reference, but it doesn’t include an adjustment for park effect. I don’t have historical park factors for DER. This is very important, and it definitely undermines the validity of the stat.
Actually, this is really just a fun stat, anyway. As Chris says, DER is a nice baseline, but it?s very rough as a descriptive statistic and very few conclusions should be drawn from it. So let’s use DER+ to describe a few things in baseball history. And let’s be careful with our conclusions.