Marichal's delivery was renowned for one of the fullest windups in modern baseball, with a high kick of his left leg that went nearly vertical (even more so than Warren Spahn's delivery). Marichal maintained this delivery his entire career, and photographs taken near his retirement show the vertical kick only slightly diminished. The windup was the key to his delivery in that he was consistently able to conceal the type of pitch until it was on its way. The kick also served to disrupt the batter's timing.