I am not American but I am of the generation who knew its stars, including many of America's best, as household names. When Ryun burst on the scene in the mid-sixties he was seen as a phenomenon. In two years, from '66-'67, he rewrote the sport and was a legend by the age of 20. He was regarded as the bar for middle distance runners until his feats were finally surpassed in the mid-seventies by Bayi and Walker and then Ovett and Coe.
But outside the US today and a coterie of marathon devotees, the name of Deena Kastor means nothing - as fine a runner as she may be. There really is no comparison; one athlete was an international colossus - however brief his time in the sun - and the other, for all her undoubted national achievements, is only a hometown hero. You can't match the best in the world, as Ryun was in the sport, as he rewrote the record book, with only being the best in your own country, as Kastor has been, however enduring that level of career. Mary Decker was the only other legitimate contender.