In every obvious way, Randy Johnson and Tim Lincecum are the polar opposites of pitching. Separated by 20 years in age, nearly a foot in height and 270 victories, they embody contrast: Johnson as the older, taller, surly left-hander; Lincecum as his younger, shorter, right-handed, more personable counterpoint.

Yet for all their differences, these San Francisco starters and Cy Young Award winners have each flung fastballs in excess of 100 miles an hour, a rarity even in the rarefied air of the major leagues.

The question, then, is how? How can Johnson, the towering lefty with the intimidating scowl, and Lincecum, the marvel of motion who has been mistaken for a batboy, accomplish the same feat in such different ways?

“It’s similar to how a Corvette and a Porsche look so different and drive so fast,” said Rick Peterson, the biomechanics expert and former pitching coach for the Oakland Athletics and the Mets. “Under the hood there are so many similarities.”