Let me see if I can get this straight. If I am ahead by a significant amount (which is a different amount from person to person), and the ER is 99% so I should either lose or almost break even if I continue to play, taking my profit before I lose it back is bad. It is better to keep playing and lose back the profits because win goals are stupid and not according to the math.

Years ago I won the math and science fair in High school using (of course) various gambling demonstrations. The math must have changed since then.