What sets apart a average swimmer from a truly great one?

Its not about talent and training only its also about the will to improve and the right mindset. I guess the great one has a bigger will to win compare to an average. The average one is not improving (much). He stay always in his comfort-zone.

And yet you are faster than a lot of others who might ask the same question of you. Oh, so true. "There are always greater and lessor humans." And also what are you calling great? I live in Pennsylvania. As far as I'm concerned, someone who swims in a lake at least once in every month of the year is a truly great swimmer. Faster, for example, doesn't make that any better.

Lots of good answers here but we shouldn't forget the importance of a great coach! Whether that coach was someone who worked with the swimmer from a younger age or later in life, the impact of a great coach can be felt lifelong. Also important is having a strong support group (family, spouse, friends) to allow that swimmer to make the sacrifices it takes to be truly great.

I like this group of physical attributes. Let’s compare two Olympians, first the most awarded, Michael Phelps: Tall - Yes long arms - Famously yes long torso compared to legs - Yes wide shoulders - Yes ectomorph-to-mesomorph build - Yes big hands and feet - Yes big lung capacity - Yes flexible ankles, knees, and shoulders - Yes strong core - Yes high lactate threshold - Presumably high proportion of fast-twitch muscle - Yes And now Cody Miller: Tall - No long arms - No long torso compared to legs- No wide shoulders - Yes ectomorph-to-mesomorph build - Yes big hands and feet - No big lung capacity - No flexible ankles, knees, and shoulders - Yes strong core - Yes high lactate threshold - Presumably high proportion of fast-twitch muscle - Yes Corey Miller is a breaststroker and Breaststroker can be shorter. As for legs, My legs are so short that I have to go to petit. I'm also average height though and Breaststroke my best stroke.

I like this group of physical attributes. Let’s compare two Olympians, first the most awarded, Michael Phelps: Tall - Yes long arms - Famously yes long torso compared to legs - Yes wide shoulders - Yes ectomorph-to-mesomorph build - Yes big hands and feet - Yes big lung capacity - Yes flexible ankles, knees, and shoulders - Yes strong core - Yes high lactate threshold - Presumably high proportion of fast-twitch muscle - Yes And now Cody Miller: Tall - No long arms - No long torso compared to legs- No wide shoulders - Yes ectomorph-to-mesomorph build - Yes big hands and feet - No big lung capacity - No flexible ankles, knees, and shoulders - Yes strong core - Yes high lactate threshold - Presumably high proportion of fast-twitch muscle - Yes Cody Miller is a breaststroke. We have different dimensions than other simmers.

I'm curious, why is a long torso comparable to legs preferable?

I'm curious, why is a long torso comparable to legs preferable? Look at a fish, long thick body, short tail with fins.

I'm curious, why is a long torso comparable to legs preferable? Well, I'm not entirely sure if the ratio itself is important on its own, but you want to be tall, and it also helps to have short legs because you can maintain a higher frequency of kick with a lower amplitude that stays within your slipstream easier. So that ends up with preferably a long torso to make up the height difference. Famously, Michael Phelps, who is 6'4", has the torso of an average 6'8" person and legs of an average 5'10" person. My checkoffs in the physical advantages column are pretty few - I'm 6'1" but with a 6'7" wingspan, and I have ridiculously flexible ankles. But I have really long legs and size 10 feet which is tiny for someone over 6'... BTW, cinc, I would say that Cody Miller probably does have some good lung capacity. You kind of have to to be effective at breaststroke pullouts with the dolphin kick these days. Also from pictures he does seem to have long arms, at least relative to his height.

Cody Miller is a breaststroke. We have different dimensions than other simmers. We do? :) That was my best stroke & events and may be again. I'm 6'4" and more Phelps-like than Miller-like. Doesn't seem to have been an obstacle. All kidding aside, I find the OP's question always fascinating. We have Phelps & Miller, both with different forms but both are unquestionably great swimmers. All those physical attributes combine with great coaching, talent, technique, drive, circumstance, and all kinds of factors that make a great swimmer. Sometimes they seem to be easy to spot early, others not as much. I find this makes swimming an ever-interesting sport because so many kinds of people bring so many different things and so much to it.

Well, I'm not entirely sure if the ratio itself is important on its own, but you want to be tall, and it also helps to have short legs because you can maintain a higher frequency of kick with a lower amplitude that stays within your slipstream easier. So that ends up with preferably a long torso to make up the height difference. Famously, Michael Phelps, who is 6'4", has the torso of an average 6'8" person and legs of an average 5'10" person. My checkoffs in the physical advantages column are pretty few - I'm 6'1" but with a 6'7" wingspan, and I have ridiculously flexible ankles. But I have really long legs and size 10 feet which is tiny for someone over 6'... BTW, cinc, I would say that Cody Miller probably does have some good lung capacity. You kind of have to to be effective at breaststroke pullouts with the dolphin kick these days. Also from pictures he does seem to have long arms, at least relative to his height.[/QUOTE There are articles about why Michael long toso and short legs helped him. He is suppose to have less drag compared to your average swimmer.