When will you "call it a day"

[JJ]

I always said I'd do it till I was 60, and then decide on a year-by-year basis depending on my ratings, enthusiam, and how well my body is holding up. It just seems a shame to me to arbitrarily pick a date when I've worked so hard for so many years to get to the level I am at now. If I pay attention to the three criteria I outlined, the choice will, for the most part, be made for me.

JJ