What Does Best Mean?

(TIME) -- There is excellence, and there is greatness. And then there is genius — cosmic, transcendent. Ruthian, Einsteinian. We know it when we see it, we think. But how do we measure it?

It is impossible to compare directly across the ages. Comparing, say, Einstein to Newton is fruitless. They stood on the shoulders of different giants, operated in different mental universes, and had completely different intellectual tools available to them. But you can measure against contemporaries. Einstein and Newton sit together in their own unique pantheon of genius because each stood so high above even his greatest contemporaries. Leibniz invented calculus. But Newton did that independently, almost as an aside, while inventing an entire physical universe that shaped scientific thought for two centuries. Einstein did that for the century since.

Godhood in sports is a less weighty matter, but, happily, more measurable. Sports yields numbers. The problem again, however, is the impossibility of comparing statistics across time. Compare great hitters. Size up, say, the contemporary Tony Gwynn to the legendary Ty Cobb. Gwynn seems to fall short. His lifetime batting average is .338; Cobb's was .366. But that is no comparison at all. Cobb was playing in a dead-ball era when gloves were smaller, fielders slower, and racial exclusion limited the pool of great players. Everybody was getting slap hits. Thus, there is really only one way to render judgment. You measure the Gap between the player and his contemporaries. You apply the "next guy" test. Then the clouds part, and the deities appear.

Babe Ruth hit 59 home runs in 1921. The next three guys hit 24, 24 and 23. Wayne Gretzky similarly laps the field. In the 1981-82 season he scored 212 points. The next two guys scored 147 and 139. Gaps like these are as rare as the gods that produce them. By 1968, no one had ever long jumped more than 27 ft. 4 3/4 in. In the Mexico City Olympics, Bob Beamon jumped 29 ft. 2 1/2 in. This in a sport in which records are broken by increments of a few inches, sometimes fractions.

In physics, a quantum leap means jumping to a higher level without ever stopping — indeed, without even traveling through — anywhere in between. In our ordinary understanding of things, that seems impossible. In sports, it defines greatness. The most striking visual representation of the Gap is the famous photograph of Secretariat crossing the finish line at the Belmont Stakes, 31 lengths ahead of the next horse. You can barely see the others — the fastest horses in the world — in the distance.

The mark of true transcendence is running alone. Tiger Woods is only 25, but one can already safely say that he is the greatest golfer of all time. How do we know? Because of the Gap. Woods won four majors in a row. Sportswriter Thomas Boswell added up the total number of strokes Woods took to win them, added the Players Championship (a fifth Woods victory in that streak and considered the next most prestigious tournament), and found that Tiger shot a cumulative 1,357 strokes. The next guy shot 55 more. And the next, 57.

The Gap is useful in finding deities not just in sport. Consider brainpower. The most classic, unforgiving test of intellect is chess, a contest in which the great masters are so evenly matched that 80 percent of tournament games end in draws. To win a match of say, 12 games, a great player might win two, lose one and draw the rest. How then do you decide who is the greatest player of all time? Easy. In 1971, Bobby Fischer played World Championship elimination rounds against the best players on the planet. Because these were open-ended matches that concluded only when one player won six games, such bouts could take months. But Fischer conducted a swift campaign unseen since Scipio Africanus leveled Carthage. He beat two challengers six games in a row, which, combined with victories before and after, produced an astonishing streak of 20 consecutive victories against the very best of his time — something never seen before and never to be seen again.

The arts, unfortunately, do not permit such precise and measurable judgments. Biologist and philosopher Lewis Thomas was once asked what record of great human achievements he would launch into space to be discovered one day by some transgalactic civilization. A continual broadcast of Bach would do, Thomas suggested, though "that might be considered boasting."

Sometimes you don't measure. You just listen.