As a test run, I took the matchup chart from
here and performed 25 iterations of the process described by Fly_Amanita. I would just like to say that the rate of convergence for this is pretty fast...
Original----Change------New---------Character
1.0000000 +0.0000000 1.00000000 Sheik
0.9687500 +0.0019027 0.97065274 Fox
0.9479167 -0.0074927 0.94042400 Marth
0.9270833 -0.0038687 0.92321459 Falco
0.8854167 -0.0000344 0.88538222 Purin
0.8750000 -0.0017297 0.87327027 C. Falcon
0.8489583 -0.0105879 0.83837048 Peach
0.8437500 -0.0142690 0.82948104 Ganon
0.7864583 -0.0249358 0.76152256 Dr. Mario
0.7812500 -0.0303421 0.75090786 IC
0.7395833 -0.0294050 0.71017829 Samus
0.7291667 -0.0225875 0.70657919
DK (+1)
0.7343750 -0.0283261 0.70604895
Mario (-1)
0.6979167 -0.0277293 0.67018738 Pikachu
0.6875000 -0.0252528 0.66224720 Luigi
0.6562500 -0.0197121 0.63653792 Link
0.6145833 -0.0360513 0.57853199 Y.Link
0.5520833 -0.0366915 0.51539183 Mr.G&W
0.5260417 -0.0343355 0.49170620 Zelda
0.4843750 -0.0448572 0.43951784 Mewtwo
0.4322917 -0.0368180 0.39547367 Ness
0.4270833 -0.0498988 0.37718455 Roy
0.3958333 -0.0380496 0.35778373 Yoshi
0.3906250 -0.0339350 0.35668996 Koopa
0.3541667 -0.0529487 0.30121799 Kirby
0.3177083 -0.0464528 0.27125557 Pichu
DK's shift over mario is probably the result of having better matchups than mario against 4 characters in the top ten: Marth, Ganon, Dr. Mario, and IC's. In contrast, mario is better than DK against only one of the top ten.
I'm a bit new to these forums.... Is there a more recent matchup chart I can try this on? Even if there were, would it be appropriate for this kind of test?