I watched Rafael Nadal play two incredible matches at the Australian Open over the weekend. In the semifinals, he defeated Fernando Verdasco in a 5 hour and 14 minute match 6-7(4) 6-4 7-6(2) 6-7(1) 6-4. He returned to the court a little over 40 hours later and defeated Roger Federer 7-5 3-6 7-6(3) 3-6 6-2 in a match lasting 4 hours and 23 minutes. If you are a tennis player, you know this is an amazing physical and emotional achievement.