Flying, spinning, bouncing tennis balls are wondrous things. The 4 to 5 millisecond impact with the court or strings looks so simple, hardly in need of any explanation, and yet, it is incredibly complex when you examine it in millisecond detail. And what you find can blow your mind! What we find out about spin is a case in point. What really matters when it comes to spinning a tennis ball? “Spin – Part 1” begins to unravel the mystery behind spin.