I wouldn't say running without a watch is a guarantee to run well, just as I wouldn't say running with a watch is a guarantee to not run well. I've run enough races to feel secure in saying I've had several very bad races while not paying attention to splits for various reasons. However, every day is different and especially when one hasn't raced in a while, it's hard to know what the correct splits should be. The one thing that only changes slightly due to gained or lost fitness is how you should feel at different points in the race. We all know that (roughly speaking) the first lap of a mile or 1500 should feel fast but controlled, the second lap should require some effort, the third lap is difficult and requires a lot of focus, and the only thing getting you through the final lap is the knowledge that the finish line is near.