Yes murdr I caught the same thing, it almost jumped off the page at me.
20mm there is a time for throttle work, but when your blowing E in turns is not that time.
To reduce speed closer to corner speed so you can turn inside someone maybe, just maybe. But not most corners.
Using the vertical really is crucial, immelman's, obliques, yoyo's are all vital tools.
The other thing that several have mentioned, but didn't really explain well, was flying in lag pursuit to
horde your E. So your chasing this bogey, and you see that 1.2k out he makes a very sharp left break turn.
Trying to get back around on you. Instead of pointing your nose at him, continue your path closer to where he turned.
Then make a smoother, less E loss turn than he did. Preferably holding an altitude advantage coming out of it.
What your attempting to do, is get behind him, but far enough back so he doesn't feel TOO threatened.
Then as he becomes more and more concerned his moves will become more violent, E wasteful. You cut across the corners because your in a position to anticipate where he's going. He's blowing chunks of E, and your flying smooth and saving yours. End result you'll have E and he's going to be flopping around on the deck without any. Now you still need to know how to USE that E you gained. But your closer to the solution.
Doing this while maintaining SA, not letting him get nose around to kill you, this is what takes time and practice.
Come see me in the TA some afternoon, I think we need to get you into a val fight.