You need to read the other guys energy state closely... in some cases, all that extra energy the other guy has can actually work against him. For example;
One of Hajo's favorite moves in his P47 is to let a 109 dive on him and he noses down at the same time. Once the 109 begins to compress, he pulls up while the 109 struggles because he has a higher airspeed. Hajo recovers and has the perch on the 109.
One of my favorites is to let the high bandit dive on me, the closer he is to a 90 degree dive the better. If he doesn't have that much alt, I'll have him burn more energy by keeping him 90 degrees AoT, since I'm slower I pull 3Gs while he is pulling up to 9Gs for the same circle. Even if he doesn't black out and end up beneath me, he will bleed energy to a more co-E state.