The thing about polls like this is the results are always going to be a product of whatever era it happens to be when the poll is taken. Already Mosconi and Hoppe are being forgotten. Take a poll 40 years from now and you'll see Reyes with maybe 15% of the vote, Mosconi, Lassiter will hardly register at all, Greenleaf? Who's Greenleaf? they'll say. Some new hotshot, lets call him Dan Thompson will get 50% of the vote. Anyone who votes against Thompson will be hounded by the others for an explanation. they'll say "Dan Thompson was the greatest player to ever hold a cue!!! I've never even heard of this Mosconi guy, he must have played back when they didn't even have tips on the cues!" "Yeah Sigel, Reyes, Hohmann were great for their time but they didn't play all the games we have now like 3-ball and 2-pocket! How can they be considered?!" It will go on like that until the thread gets really heated and nasty flame wars occur.
I'm beginning to think we should't even compare different eras, if someone can dominate their era that should be enough to establish them among the all-time greatest.
Bobby