How come the infield grass doesnt die when it is covered with the tarp?

Question:when i cover my grass at my house with anything for like 10 minutes, the grass dies, yet at a ballgame, the grass is fine. why?

Answers:
You have an ultra-sensitive lawn.
At the ballpark they only leave the tarp on while it's raining.
My kids had a tent with canvass floor up on my lawn for three days and nights and the grass still survived.