I have been (mostly) playing Jazz now since about 1985. THe level of gigging has gone from minimal (4 or 5 a year) to overwhelming (120 a year). With some rare exceptions, the bands have not been rehearsed and, in many cases, have included people I have rarely played with. Most of the tunes I have played most of the time have been things I am only superficially aware of and I have been reading chord charts and improvising around sequences the knowledge of which is, at best, peripheral. Some of these charts are going past like s*** off a stick and there are lots of strange symbols and extensions designed purely to humiliate me.
A lot of the work I have done is massively flawed and I deeply admire those players who can make something beautiful out of a sequence that, by its very nature, puts rocks in your path. I don't consider myself to be one of those players. I can find my way around a basic standard but lob in a few slash chords, some obscure harmony and I am easily thrown. I can usually figure out a way through, given time, but, because most of the gigs I do don't allow for that level of preparation, that time is mostly after the fact.
Playing Jazz, as an improvising Art form, is a high risk undertaking.
I was wondering, therefore, given all the above 'environmental factors', why I think it is EVER going to be anything but grimly inadequate.