All above replys are spot-on. A longtime ago, I was bounced by Shane in a higher-than-me P47,, I knew it was him (he was GOOD!), and I just kinda' gave up. He PM'd me and said; "Dont ever give up! Learn defensive tactics!" And, he was kind enough to show me some of his (via films he sent).
There's no single big secret answer to BnZ defense.. it's a series of "things" that you gota' master so that they're all a "reflexive action" without thought. THEN, being bounced from hi-6 is almost fun..
Like mentioned above, PATIENCE, is the key. You must be a master at snap-views, and be able to fly and land a plane while looking out the rear-view.
This is my fave tactic (there are many that work), from which I've nailed some great P51 pilots with forced overshoots.
High P51 overhead, and you're making for base, RTB. Here he comes, nose down, distance closing on you. Rear-UP-view, watch his wings.. manuever plane so that he's deadnuts on approach to your 6,, 20 deg. nosedown to gain speed.. like your trying to escape. (somewhere, an AH pilot is smiling! Ah! He's running! YES!)
At d' 1000 (still watching him out rear view), tip right wing straight up & slightly pull back on stick.. low-G left turn..
When his wing goes up, (he's now committed to the turn w/ you!),, pull hard back on stick, hi-G turn,,
20% of the time, you'll see his wings straighten out, (a wise pilot), and he'll abandon that pass, zooming back up for alt.
80% of the time, you'll see him try to cut inside your circle to pull lead for the shot. (risky, eager, pilot). This is the fun part!
At about d'400 (still watching enemy crawl up ur arse out rear view), both of you in 90 deg bank hard left turns,, do this:
Chop power to idle, and push stick full forward to the hilt! You'll RED-OUT instantly,, count; thousand-one, thousand-two, thousand-three, thousand-four..
Then, (in this order)=> stick over to right & back, and hit FULL WEP POWER.
Think of trying to roll your plane level, going straight up, and barrel rolling slowly to the left. (confusing sounding, but simple, as you'll see)
As RED-OUT clears, use view keys frantically to see where the bugger is.. 90% of the time, he'll be flopping around slightly below you on the left side, trying to figure out what in hell happened to his perfect bounce?
You'll get a passing snapshot at the very least if you can get him in view quick enough.. At the very worst, he'll try and zoom up, with 50% of his e wasted.
Set yourself on course to escape, and repeat if need be, turning to the right the next time.
This is (was?) one of the coolest Shane moves that works for me every time. Negative-G pushover under close 6 O'clock attack. Interestingly enough, I was reading one of the many WWII fighter pilot books. Found that Eric Hartmann described (and used) this same exact tactic, over & over, and attributed his longevity (and life!) to this tactic.
Good luck,
RV6