OPEC hasn't been effective at controlling prices for some time now.

Every supplier in a marketplace has the ability to lower marginal prices in a price war.

Only effective cartels can raise prices at will. And OPEC’s power to do this is pretty clearly diminished, if not destroyed, by expanded US and Russian capacity.

Again you must be sleeping last two weeks. Saudis single handedly destroyed oil prices.

The Saudis most certainly did not raise prices, which is the point I'm making. I'm well aware that the lowest cost producer can lower prices at will.