Originally Posted by Benhur
Say you are looking at the open era from the perspective of someone in 1982. You see the 80% career mark being reached pretty regularly every 3 years or so. You think it is a common thing for the top players.
Connors broke that mark in 1974. Then Borg in 1978 (or rather 1977 when the DC record is included). Then McEnroe in 1979. Then Lendl in 1982. And they never dropped back below that mark through their careers.
Then this regularity is broken after 1982, and there is 25 year wait until Federer reaches that mark again in 2007, followed by Nadal in 2008. It looks like Djokovic will break it also this year.
Similar thing with single year percentages above 90%. In the 16-year period from the beginning of 1974 to the end of 1989, such percentages occurred a total of 13 separate times -- almost every year. Then there is a 14 year hiatus until Federer does it again in 04, 05 and 06. Then Djokovic in 2011.
What to make of something like this is not clear. In the 70s, 80s and 00s, the best players of each respective decade got there. Not so in the 90s.
Were these anomalies due to the fact that they had stronger competition in the 90s, or was it because they were less dominant?
That's a damn good question. It is clear that the greatness of a player is strongly linked to the playing conditions, especially when some feat are clustered in a short amount of time. For example, the careers slams we see now (I guess we will see another soon) are allowed by the surfaces homogenization.
But why nobody couldn't reach very high winning percentage in the 90's? Let's make some hypothesis:
1. The idea of a stronger competition that before make sense, as tennis developed itself a lot in the previous decades. The "journeymen" were more accomplished than before, which made it harder to be a second tier player, which means they were better and made it harder for the top tier to dominate them. The weakness of this hypothesis is that the 90's field was relatively strongly divided by surfaces. Mainly, the idea that a harder competition leads to better players at the top is valid if we are considering level in absolute value, but it cannot explain the difference between the top tier players and the second tier players: why would it be easier for a player competing against weak opponents (in absolute value) to become strongly better than them, than it would be for a player competing against strong opponents? Which means: how is the domination linked to competition strength.
2. The two players who had the means to do it didn't do it for "fortuitous" reasons. Sampras was focused on winning slams, he had the best chance on faster surfaces, so he focused on faster surfaces and didn't care to really try on clay and in the smaller tournaments. Agassi had his motivation issue and never realized his true potential. They prevented other players to do it (although I don't see who else could have done it, even if they weren't there).
3. Unknown reasons led to an overall weak field in the 90's and early 00's.