Azzurri
Legend
It all depends at what level of performance you choose to measure the consistency. If you are talking about being top 2, top 3, top 4 and top 5, then Agassi is seriously outperformed by several players in terms of longevity. But if you lower the level to the top 10, 25, 50 and 100, then he is up there. All things considered, I would say Connors, Lendl, Mac and even Sampras had a more impressive longevity overall because their numbers are much better at the higher levels.
Most Years in Top 2
Jimmy Connors 8
Ivan Lendl 7
Roger Federer 7
John McEnroe 6
Pete Sampras 6
Rafael Nadal 5
Bjorn Borg 4
Stefan Edberg 4
Andre Agassi 4
Most Years in Top 3
Jimmy Connors 12
Ivan Lendl 10
Pete Sampras 9
Bjorn Borg 7
John McEnroe 7
Roger Federer 7
Andre Agassi 6
Most Years in Top 4
Jimmy Connors 14
Ivan Lendl 10
John McEnroe 9
Pete Sampras 9
Bjorn Borg 8
Andre Agassi 8
Most Years in Top 5
Jimmy Connors 14
Ivan Lendl 11
Pete Sampras 10
John McEnroe 9
Stefan Edberg 9
Boris Becker 9
Bjorn Borg 8
Andre Agassi 8
Most Years in Top 10
Jimmy Connors 16
Andre Agassi 16
Ivan Lendl 13
Pete Sampras 12
Boris Becker 11
John McEnroe 10
Stefan Edberg 10
Most Years in Top 25
Andre Agassi 18
Jimmy Connors 17
John McEnroe 15
Ivan Lendl 15
Stefan Edberg 13
Pete Sampras 13
Boris Becker 12
Most Years in Top 50
Jimmy Connors 18
Andre Agassi 18
John McEnroe 16
Ivan Lendl 15
Guillermo Vilas 14
Yannick Noah 13
Stefan Edberg 13
Michael Chang 13
Pete Sampras 13
Carlos Moya 13
Most Years in Top 100
Jimmy Connors 19
Andre Agassi 19
Fabrice Santoro 18
Ivan Lendl 17
John McEnroe 16
Guillermo Vilas 15
Boris Becker 15
Magnus Gustafsson 15
Pete Sampras 15
Thanks for the info, good stuff. I guess I will have to change my stance on Agassi a bit and say "one of" the most consistent w/Connors being the obvious choice.
I have always been a big Agassi fan (2nd to Mac), so I am a tad biased.