In the end, it is probably a combination of skill and capacity. Your potential may very well be limited by a bad connection, but skill only fills up that bar of potential. It is of no use to have a large bar of potential with close to nothing in it. The exploitation of bugs covers all of that skill up, however, as the game may not be won properly, if at all, with the abuse of the bugs. A computer with an insufficient processor or video card may also hinder skill, but that does not seem to be a common problem as of today. Dueling opens up more space for potential, but does not necessarily fill it all the time. Experience under various conditions such as lone reliance, teamplay, and handicaps are required to improve at all. Of course, people probably do that unintentionally and simply play the game. Conditions like these apply to just about everything related to it.