I didn't pay attention to the Shangai 1000 until today. I checked the draws. There are 7 players who already retired in a draw of 56 (1/8 of the draw!), most of them ranked in the top 20. That of course in addition to the players who didn't play (Federer, Murray). Can someone put this in the right context and tell us what's going on? Players burning out at the end of season? Issues with the Shangai surface? If players are burning out, should the ATP make the US Open the last mandatory tournament of the calendar year?