What does this mean, "The game of doubting itself presupposes certainty?"?

People often get themselves tangled up into thinking that is more like a knot than a straight rope. Just because a statement entangles itself senselessly into nonsense does not make it an intelligent comment. It is far better to speak straightforward or re-state it in such a manner that I do not have to unknot the knot in order to take it in. Re-think, and restate in a straightforward manner.