What does it take to be a World Champion or World’s #1? What qualities do chess players have to possess to reach that level? OK, I don’t mean World Knockout Champion. I mean legendary champions like Kasparov, Karpov, Fischer, Spassky or Chiburdanidze, Gaprindashvili, Xie Jun, etc. The forum is yours! 
Chess Daily News from Susan Polgar
I think you’re the only one here that knows the answer to the question. We can only guess and guess & guess. So let me guess: complete devotion to chess. Not many boyfriends nor girlfriends, only – friends.
To attain that level, I agree that total devotion to chess and chess alone is necessary. Does not leave much time for anything else. The person, I believe, would need to be very “left brained”, meaning very good at logic, linear (boolean) mathematics, etc.
I hope to achieve Class A some day, but I’m finding it difficult to get the time to study and play OTB tourneys, so I can only imagine how difficult it is for people aspiring to reach GM status.
According to me world champions means consistency. Only the person who gives consistently good results over a period of time can be called world champion. It takes a lot of hardwork to do this.
Todays knock out champions loose next tournament in a bad way.
good memory
and as in anything else(music,golf,art).
VERY Early exposure to the skill being learned
Many Many hours spent daily on that to the possible detriment of other skills.
2 elements which must go together. Talent & work. Talent is a very broad based term here. It covers photographic memory, the ability to analyse a position many many moves deep including branches & sub branches quickly & correctly, correct conceptualisation of the positional & tactical demands & nuances of the game at hand etc
The 3rd quality above can be improved by work & experience, but the 1st 2 are God given.
A healthy body and a healthy mind.
What does it take? World Champion minded parents (at least one of two) for starts. You need to be born in a chess community, a village kid has no chance.
Since the question here is “WHAT IT TAKES TO BE A WORLDCHAMPION”, I think, we shouln’t be talking about the start or birth, but what differenciates between the #1 among his/hers closest rivals. I would select them in this order:
1.) Nerve (incl. resilience)
2.) Stamina/fitness
3.) Courage and willinness to dig deep when it counts
4.) Ability to change tactics when something doesn’t work. In other words, throw in an element of surprise every now and then, which keeps your opponent guessing.
Most often these may matter as talent-wise a Kasparov, Anand, Fisher may be very nearly equal, but these other differences make significant contributions to their results.
– Gans
US