What do you consider "a generation" in terms of tennis?

This is a spin-off thread of CmonAussie's thread on "the current generation of players", in which he listed Nadal and Rusedski in the same generation.

For me, a "generation of players" spans roughly 5 years. In that way, a player with normal-length career of ca 10 years will get to play opponents from two generations before as well as two generations after. And he will probably play at his highest level for five years, say from 23 to 27 years.

With my definition of generation, Agassi's (*1970) generation spans from Becker (*1967) to Rafter (*1972), but it doesn't include Edberg or Rios. Fed (*1981) and Nadal (*1986) are one generation apart.

Any opinions on this?

I agree with what you said, but it also depends on "who was successful" at which time. I guess there would be people putting Nadal and Gasquet to era of Federer, Nalbandian, Roddick and Hewitt, while the 1988ers are like something brand new - with JMDP, Korolev and Cilic (and maybe de Bakker).

For me, "generation" is determined by how well the players are playing, not their age.
"New Balls Please" was my favourite generation...

IMO, 5 years represent a cohort, and you can use cohorts to compare one generation to the next. When discussing Roger or Pete, each has a cohort equal to his age +/- 2 years.

I consider 10 years a generation, about equal to the peak years of a player's career. Pete and Roger are separated by one generation.