Sure!
who is the greatest chess player of all time?

Why do all the dumb americans say Fischer. Kasparov is way better you noobs.
According to the ratings work of Professor Arpad Elo, Fisher was the highest rated player in the world from 1963 until he quit after winning the title in 1972. Not a bad run.
Fischer's "performance rating" in 1971 reached 2895, after the Taimanov and Larsen matches.

A number of the dudes (and dudettes) that I shared credit-rolls with were also enthusiastic chess-players... although they weren't much good.
Kiefer Sutherland, for one.

Answer: The greatest player
Yes, but it doesn't say "Greatest at what?"
According to the ratings work of Professor Arpad Elo, Fisher was the highest rated player in the world from 1963 until he quit after winning the title in 1972. Not a bad run.
The first official Elo rating list was published in 1971, and this is a good summary of the world #1's:
http://en.wikipedia.org/wiki/List_of_FIDE_chess_world_number_ones
There were a few unofficial lists before though, like this one from 1967 with Spassky and Fischer sharing first with 2670:
http://www.olimpbase.org/Elo/data/Elo1967.pdf
In the PDF above Chess 9/1967 calls it "amusing" that Fischer can share first in spite of his comparatively bad results against the top players and means that his rating is caused by his results against "weaker" opponents.
In general Fischer was not yet seen as the best player, a big poll among the GMs in the Lugano Olympiad 1968 ranked Spassky and Petrosian as the two strongest players, with Fischer in third.
Shorter than GM Short?