MiG-15 is difficult but not unbeatable. Don't go too fast at the merge or he will end up inside your turncircle before you're out of the first turn. If you can force him into a rolling scissors, you have good chances. Keep the fight at altitude seems good. Only go vertical with him if you have the speed, can see that you can get pipper on within two or three loops, and have the altitude to get out of it, should you fail. But don't get me wrong, it's not easy.