Here's a quick thought experiment, before you see the result in a YouTube video.
Let's say you're standing atop a 415 foot high dam, and you drop a basketball. Barring any major wind, how will it fall? Will it go straight down? Will it curve? Okay, now that you have given that scenario some thought—what if you do the same drop, but give the ball a little backspin? Will that change the way it travels to the ground?
Chew on that for a moment, then check this out: