I think it would be great if the ATP World Tour Finals was a multi-surface or variable surface event. (Maybe it used to be, I don't know much about tennis going back 8 years or so.) I think the logistics of playing one tournament with different surfaces would seem to be fairly impossible (finding a facility with 4 show courts with different surfaces for example). If it were fathomable it would be cool to see players' matches randomly assigned to a surface. I cannot really think about how this could be accomplished though. If they cannot do a multi-surface tournament (2 to 4 surfaces), I think they should at least look into making the tournament rotate surfaces by year. For example 1st year would be an outdoor hard surface, 2nd year would be clay, 3rd year would be grass, and 4th year could be indoor hard. I think players would probably complain about playing grass or clay after the indoor hard court season but I think they should still be able to handle it. Players often have to perform on an out of season surface for Davis Cup matches so I don't think there should be any problems with this. Is this a good idea? Yay or Nay?