The Khopesh Curve

Here's something of a follow-up to last weekend's discussion of different approaches to XP Awards on Wandering DMs. I've previously looked at the radical switch in monster XP awards that occurred between OD&D Vol-1 (1974) and the Sup-I Greyhawk supplement (1975; which then became the basis for all XP awards in Holmes Basic, B/X, Mentzer, AD&D 1E and 2E, etc.). But I've been looking for a clearer visualization of that curve.

Here's the raw data just for Sup-I base XP awards (not including special abilities, although that just shadows this data pretty closely). You can see that the HD 1 to 8 range is where XP awards have been depressed, following roughly a quadratic curve; and then the higher HD 9 to 20 range, where the XP pretty much follows the same linear 100-per-HD award seen in the earlier Vol-1:

Now, here's a cleaned-up version showing just the regressed curves in the two pieces (using Wolfram Alpha):

For future identification purposes, I hereby name this shape the "Khopesh Curve":

Side note: The Wandering DMs are at TotalCon in Marlborough MA all this weekend -- check out our live streaming updates and if you're there, please say hi to us in person!