This was another interesting thread to me having been a golfer/ golf instructor. Many of the challenges are the same but in golf some of the variables can be extra confounding. For instance the offset error is 3 or 4 feet as opposed to an inch or two . Possibly the greatest golfer ever virtually no one has heard of, Moe Norman, said that golf requires both an art and a knack. The art being the mechanics and the knack being an understanding of the concept of the task and how the mechanics work for the individual. If we look closely at the best pros they are all different but, there are a great many things that they do virtually the same. I would think nearly all of them release their darts at the same point in their throw. In my opinion, they are more accurate because their hands and thus the dart on on the correct path longer which in turn gives them a larger window to release the dart and still have it follow the proper path to the target. In golf we would call this having a wider flat spot at the bottom of the swing arc. This means that they still miss but, their misses are more accurate than the rest of us. As for practicing an inaccurate throw I will add this dimension. Consistently inaccurate is something to work with whereas inconsistent and inaccurate is not.