If he had been racing against the winner of the 1904 Olympic marathon, he would have won by nearly an hour and a

half.

If he were racing against the winner of the 1904 Olympic marathon, he would win by nearly an hour and a

half.

If he raced against the 1904 Olympic champion, would he win by an hour and a half?

... has an arm span that is shorter than his height.

...has an arm span that is equal to his height.

It's a conditional

It's a mistake by the speaker

It's a question.

... the evolution of the human species in the last 100 years

... what is really at the basis of the improvement in athletics.

... how Olympic marathon champions in the 21st C. run one and a half hour faster than the Olympic marathon champion of 1904.