Twenty-nine is about the age at which visual acuity often begins to deteriorate. And visual acuity is critical for hitters. Big league hitters have no faster reaction times than teachers, doctors or lawyers. But they have an average visual acuity of about 20/12, meaning they can see from 20 feet away what I have to scoot up to 12 feet to discern. That superior vision helps them pick up on anticipatory cues such as the “flicker,” or the flashing pattern of seams on a ball as it spins toward them. Subconsciously registering the flicker allows them to predict where the ball will go well before it’s halfway to home plate.
Maybe the best Arod article i’ve read