For those of you who haven't seen it...
http://www.truechess.com/web/champs.html
Basically, this guy did a very detailed computer analysis using the 2007 version of Rybka and a modified version of Crafty to test the middle-game moves of all the World Champions (to avoid progress in opening theory), and he ranked the various players based on rate of blunders and percentage improvement over the average Grandmaster's move...with tables showing the rankings over 1, 2, 3, 5, 10 and 15-year periods.
It may or may not be a surprise that Fischer was found to be the most accurate human chess player that's ever lived on almost every list. The only one who topped a list other than Bobby was Capablanca, over the 15-year period.
Perhaps it may be another surprise that, over the 1, 2 and 3-year peaks, Mikhail Botvinnik was found to be more accurate than Garry Kasparov.
As an armchair fan, this was certainly interesting to discover, as I've been led to believe that Capablanca, Fischer and Kasparov are the three best players ever, however, it may seem that Botvinnik was actually the most talented Russian chess player ever (though Kasparov may remain the hardest-working).
This also, perhaps controversially, jibes with Nakamura's claim that Kasparov's strength came from his superior opening preparation, since over all short-term peaks, his middle-game accuracy is very good but not outstanding amongst the other World Champions.
I found this all to be interesting stuff, and I would love for a very similar analysis to be done now with Houdini 1.5...though it may be that at a certain level above human-strength, the computers extra calculating ability helps only when competing against each other, and they will all find the same mistakes in the human game database. Though it would be worth it just to see where Magnus and Aronian would rank.