OK, I don't really believe the previous statement and a subjective list such as IMS has created will certainly stimulate arguments and debates on not only the list itself but how the participant's list was assembled. By no means is there a perfect system but I would contend that to not primarily rely on statistics allows for a fairly significant bias against drivers in the first half of IMS's century of racing who most of us never saw (i.e. pre-1960).
As is typical with me, I employed some simple statistics to assist in selecting and ranking from hundreds of drivers. Cool, unemotional, unsympathetic numbers will tell a vast majority of what I needed to know and after a bit of deliberation, I settled on a formula which weighed wins, laps lead, number of poles, number of races, and top-5 finishes, to varying degrees.
For me this eliminated a great deal of debate about drivers who were in the top 25-28. The remaining 5-8 spots would require some subjectivity as there were many drivers with 1 win and some drivers with no wins who fell in very close proximity via the statistics. In an homage to the Indy Press Corps' Last Row Club, the final row of 3 was reserved for the 3 greatest drivers to never have won. All other inclusions had at least one win to their credit.
Without further ado, I submit my Greatest 33 to have raced at the Indianapolis 500:
1-Al Unser 2-AJ Foyt Jr. 3-Rick Mears
4-Wilbur Shaw 5-Bobby Unser 6-Johnny Rutherford
7-Mauri Rose 8-Louis Meyer 9-Mario Andretti
10-Gordon Johncock 11-Helio Castroneves 12-Emerson Fittipaldi
13-Bill Vukovich 14-Rodger Ward 15-Arie Luyendyk
16-Al Unser Jr. 17-Ralph DePalma 18-Parnelli Jones
19-Tommy Milton 20-Tom Sneva 21-Dario Franchitti
22-Jim Clark 23-Dan Wheldon 24-Jim Rathmann
25-Bill Holland 26-Billy Arnold 27-Bobby Rahal
28-Scott Dixon 29-Jimmy Bryan 30-Jimmy Murphy
31-Michael Andretti 32-Rex Mays 33-Ted Horn
The group of tightly-scored drivers who just missed making the list were: Danny Sullivan, Buddy Lazier, Eddie Cheever Jr., Sam Hanks, Peter DePaulo, Mark Donohue, Bill Cummings, Pat Flaherty, Troy Ruttman, and Howdy Wilcox.
Of course I don't really think my list is better than anyone else's, however I will say that a fair bit of thought and bias-reducing consideration went into the making of the formula which produced a majority of my list.
I would love to hear what you see as major misses or unsavory inclusions that populate my list...