As an aside, I think it only is in chess (maybe because of Fischer) many do not rank longevity as #1 as the most important criteria. No one would suggest that a Federer with 20 Grand Slam titles would be behind a player with two just because the latter won his two titles with a bigger margin.
Fischer had the best 2 years in a row EVER!!! Prove me wrong.

I think it was Kasparov that said something like the best player or greatest world champion was the player who had the greatest distance between #1 & #2.
So umm....... do the math.
Kasparov didn’t say that :-). But if he had said that, I guess Philidor or Morphy would have good cases to be the greatest ever. Unless one uses the Chessmetrics system, then it would be Steinitz. However, this way of ranking the greatest players ever are for some reason never applied on other players than Fischer. :-) In that case Topalov would be greater than Anand and Kramnik.
What Kasparov did say was that there are many ways to rank the greatest players, one of them being distance to #2 at one point in time. And if one used that criteria, Fischer might be #1. If one uses criteria like World Championship titles, time as #1, top events won, etc, others would have better cases.
does that even mean rating? cuz if it meant actual playing strength, it would mean much more.

As an aside, I think it only is in chess (maybe because of Fischer) many do not rank longevity as #1 as the most important criteria. No one would suggest that a Federer with 20 Grand Slam titles would be behind a player with two just because the latter won his two titles with a bigger margin.
I see it sometimes. In football many rank Maradona as the greatest because he was so far ahead in his 2 years at Napoli and at the '86 World Cup for example. I think people are fair in picking a genius who burned brightest for a short period of time than more 'Steady Eddy' types.

Some online sources report a range from 180 to 187.
Okay, what sources?
You are a chess player, not a nincompoop. Try searching for "Bobby Fischer IQ." You will get lots of hits.
As an aside, I think it only is in chess (maybe because of Fischer) many do not rank longevity as #1 as the most important criteria. No one would suggest that a Federer with 20 Grand Slam titles would be behind a player with two just because the latter won his two titles with a bigger margin.
I see it sometimes. In football many rank Maradona as the greatest because he was so far ahead in his 2 years at Napoli and at the '86 World Cup for example. I think people are fair in picking a genius who burned brightest for a short period of time than more 'Steady Eddy' types.
Football is a bit of a special case since it is not an individual sport with measurable results. But if A won many gold medals in javeline or high jump no one would suggest that B was greater for winning once, with a bigger margin. Like no one would say Graf winning a Wimbledon final 6-0 6-0 was all that relevant compared to total number of Grand Slams. Compare the lists of number of Grand Slams or Gold medals with the lists of biggest margin to #2 in a final. No one would ever bother constructing the latter. But since Elo rating vs opponents on one rating list is the only criteria where Fischer ranks very high it is more common to refer to it in chess discussions, where still no one would use the same criteria to rank other players, for example Topalov vs Anand or Kramnik, or Morozevich vs Caruana.
I just always found the distance thing illogical. Have Kasparov and Fischer born at the same time and both playing equally well 200 Elo better than all others until they are 50, winning 50 super tournaments each and 10 World Championships. Suddenly they are both now behind Topalov in greatness for not having a bigger distance to #2 than he had. Other criteria have to be looked at, and to me the overall career achievements are more important, even if distance to #2 of course also should be included.

As an aside, I think it only is in chess (maybe because of Fischer) many do not rank longevity as #1 as the most important criteria. No one would suggest that a Federer with 20 Grand Slam titles would be behind a player with two just because the latter won his two titles with a bigger margin.
I see it sometimes. In football many rank Maradona as the greatest because he was so far ahead in his 2 years at Napoli and at the '86 World Cup for example. I think people are fair in picking a genius who burned brightest for a short period of time than more 'Steady Eddy' types.
Football is a bit of a special case since it is not an individual sport with measurable results. But if A won many gold medals in javeline or high jump no one would suggest that B was greater for winning once, with a bigger margin. Like no one would say Graf winning a Wimbledon final 6-0 6-0 was all that relevant compared to total number of Grand Slams. Compare the lists of number of Grand Slams or Gold medals with the lists of biggest margin to #2 in a final. No one would ever bother constructing the latter. But since Elo rating vs opponents on one rating list is the only criteria where Fischer ranks very high it is more common to refer to it in chess discussions, where still no one would use the same criteria to rank other players, for example Topalov vs Anand or Kramnik, or Morozevich vs Caruana.
Do you remember the name Bob Beamon. He was an American long jumper who won the 1968 Olympic gold medal in the long jump.
He was one of the favorites to win the event, with a personal best of over 27.5 feet. But it was the way he won which made him an immortal in the sport. His winning jump beat the previous records by nearly two feet. It was the stuff of legend. The record stood for over two decades.
Fisher's career was the similar. He was one of the elites in the chess world since 1962, and a recognized prodigy, but it was his championship run from 1970 to 1972 which cemented his legendary status.
Beamon is a good comparison with Fischer. Kasparov could be Lewis and Lasker Owens. No Carlsen in long jump though. The best jumpers nowadays hardly jump longer than Owens did some 85 years ago.
No world records in chess though, I now read that Beamon said Mike Powell was the greatest ever for having the longest jump, but few would say that this or that chess player was the greatest for having played one game or an event with every move the suggestion of the strongest engine or something like that. Powell said Lewis was the greatest long jumper, by the way, and ranked himself as the second greatest. He said he wouldn’t switch his world record for three of Lewis’ Olympic gold medals, but maybe for four.
But in many cases winning titles was no less important than who held world records. I recall Italian long distance runner Alberto Cova, who never was close to any world records, but had a great finish which won him Olympic, World Championship and European Championship golds. Maybe he would rather have held a world record, but I think the long jump records have been more iconic because they ”never” are beaten, only once in 52 years.
Jesse Owens result from 1935 would have won him the bronze in the 2012 Olympics and gold in the latest US Championships in 2019, by the way. None of the ten longest jumps ever were made after 1991. The longest jumps by women are even older. Other eating habits in the 80s I guess :-)

You are a chess player, not a nincompoop. Try searching for "Bobby Fischer IQ." You will get lots of hits.
I'm aware of such sites. All I've seen just say stuff like 'he reportedly had an IQ of 181' without providing any evidence. If you can't name any source that does provide evidence then I can presume you haven't seen anything that isn't just made up.

I don't think everyone has to be super logical when ranking players. Many see someone who steamrollered the best players in the world like no one ever has (unless you go back over a hundred years to when it was much easier to do such a thing), demonstrated the best raw chess ability (relatively speaking taking into account general advancement) and captured the imagination like no one ever has as the greatest. And what's wrong with that? It's all just opinions.
Evidence?
The ”evidence” is someone that after Fischer had become a famous chess player estimated what result he ought to have had on such a test :-)