1. A legend almost always will have played for us for a 10 year period or very close to. Its hard to think of someones Chelsea career as legendary when it lasts for just a few seasons. So, tenure is for me an important component.
2. Really related to the above is loyalty. Whilst players like Speedie, Walker, Spackman and Dorigo had great careers for us when push came to shove they jumped like rats from a sinking ship when it suited them. I don't rate any of the above as Chelsea legends for their lack of club loyalty. In Poyet and Duries case by joining Spurs they will never be regarded as anything other than Judas'.
3. Quality of player. Chelsea fans like all fans really appreciate 2 things in a footballer: skill and effort. Players like Zola had skill in abundance whereas Bumstead was more of a trier and gave 100% commitment to the Chelsea cause, both equally admirable traits.
So, to summarize these are my criteria:
Length of service, loyalty, and quality of play.
These are my legends from my time following Chelsea:
John Bumstead
Kerry Dixon
Steve Clarke
Dennis Wise
Gianfranco Zola
JT
Frank Lampard.
Others I regard as cult heroes would be: Pat Nevin, Dan Petrescu, Luca Vialli and Joey Jones (there are others, these are a small sample). I would stop short of calling them legends though simply because they werent here long enough.
My 3 tiered system is thus:
1. Legends = Great play + length of service + loyalty.
2. Cult heroes = Great play + loyalty (didnt leave club with bad blood).
3. Player = anyone who played for Chelsea.
Ive given this a lot of thought in the past Id be interested to know what people think of my criteria.