I agree with Woolwich. Unless you are playing to a click then time is bound to fluctuate a bpm or three from beginning to end. More than that and you have a time problem. Unless of course that is by design.
Funny thing was said to me last night. I jammed for the third time with a group of guys. Just for fun. No real intent on playing out, at least not yet. Last night the bass player didn't show so the time was all on me. Until I started playing with these guys I hadn't played with people for 15 years. And I know that I need lots of brushing up on stuff. But the lead singer said to me after we were done, that when I lay back and try not to play too loud, my pocket isn't great. But he said when I let loose and play harder, he said I really lock into the pocket and sound a lot better. At this phase of my playing days, at age 57, I'll take any compliment I can get. I took it as a compliment rather than a critcism. Although it clearly points out that I need to shake off the rust. And that's exactly what playing simple classic rock will do. I hope I didn't derail the thread.