Challenge?

I love it when tennis players challenge line calls. It adds so much more to the game. First, I like how unlike football challenges, you find out the result right then and there. Second, I like how the ball tracker thing is so clear with the calls. There isn't much wiggle room. It's either in and out. Touches the line or not. Lastly and my favorite part is the crowd's reaction when they show the ball on the monitor. I LOVE how the crowd goes: "oooooooooo" when the ball is slowly in the air and then the "ahhhhhhhhh" when it bounces. It's my favorite part... "oooooooooooooo" "ahhhhhhhhhh" (cheer!)