As Lu Mingtsu has said, the pitcher throws the ball at a speed of around 140 kilometers an hour, and it takes good visual acuity for the batter to judge the ball's line correctly.
呂明賜曾說，投手投球的球速約每小時一百四十公里，打擊手需有好視力才能捉住球的動線，看球才看得準！