As soon as the faster plane starts to extend out away from you, you can either (a) chase him but go into a climb that will keep your speed around 200-250 so that when he reverses you'll have some maneuvering speed and some altitude to work with or (b) reverse your direction and head for a friendly plane or airfield.
The idea is that the faster plane will determine when the attack will occur, but you can determine how much speed you'll have when you engage. Typically, its LA-7s, Typhoons, P-47s, 190s, and Mustangs that will do the extending, and unless the bandit is doing a vertical maneuver to dance on your head, the next attack will be from the front quarter, such as a head-on.
There are a couple of times when an HO will be to your advantage (a) when you have bigger guns than him and/or (b) when you have nose-mounted guns and he doesn't. Nose-mounted or cowl guns will allow you to begin landing hits sooner than wing-mounted guns due to the convergence. P-38s and Me110s can lay down some serious firepower in a very narrow cone, so they'll usually win most HOs (assuming they don't collide with the debris of their kill). The FW190A8 will win most HOs, except against P-38s, 110s, and the P-47 (eight .50s can cover a lot of ground, and the rate of fire is much better than the 190s). I've detonated Hellcats with a 190a8 head-on attack. Never underestimate the firepower of four 20mm and cowl-mounted 13mm.
If you find yourself on the short-end of an HO, such as if you're flying a Spitfire V and the enemy is in a 190, then you can do a barrell roll and spoil his shot. He'll blow past and you can either try to get a quick reversal on him (depending on the relative rate of closure) or you can extend out in the opposite direction from him and get your speed back up.
This only works if you're a Knight. If you try this against a Knight, your wings will fall off, your computer will lock up, your bank account number will be broadcast across the Internet, and you'll be added to the email listings for sheep porn sites.
