Front242 said:
If they did that Nadal would probably have less than 13 slams and be injured a lot more.
Wait, what? I like you man, but this is a bit far-fetched. Nadal might be injury prone, but he's not made out of glass. How many Masters finals does Nadal reach per year? 5? Let's say 6 (and even that is a bit of a stretch but let's assume it's a REALLY good year like the one he had in 2013). You mean to tell me that 6 extra best of 5 set matches, stretched out over an entire season (as opposed to being played back-to-back and thus potentially taking their toll), most of which WILL NOT go the distance anyway, are going to injure him "a lot more" and somehow tamper with his slam results?
Even in Nadal's busiest time of the year -- the clay court season -- he has historically won an overwhelming majority of his masters 1000 finals there in straight sets. So if it were a best of 5, you're probably adding a set to each match (making them 3 setters, something you can play in a best 3 set match if it goes the distance)...hardly career threatening stuff.
Let's agree that his FO results wouldn't have been affected since he's just that good there. What other slam wouldn't he have won? There are no masters 1000 events before Wimbledon so it's not like he would have gotten there tired/injured in 2008 or 2010. There are no masters 1000 events before the AO so I doubt his 2009 result would have been any different.
At the 2010 US Open, Nadal didn't reach a masters final that summer so he would have been just as fresh (and in fact won all of his 3 clay court masters finals that year in straights, so adding a set to each one wouldn't really have ruined his year).
At last year's US Open, Rafa did win both Montreal and Cinci, but did so by spanking Raonic 6-2 6-2 and going through a serve fest against Isner to win 7-6 7-6. Adding another set for him to beatdown Raonic wouldn't have altered his results, while another tie-breaker over Isner is hardly stuff of physical suffering.
The main problem with the best of 5 set format in Masters 1000 finals is back-to-back tournaments like IW and Miami or Madrid and Rome where a long five setter might result in the finalists pulling out (a la Fedal after Rome 2006). But even that to me, is a rare occurrence (a lot of ifs and buts).