-RWR is your best friend in BVR engagements, especially the TEWS in SF2 series, not only will it tell you which direction is the threat coming from, but also what it is and to some degree what is he doing(scanning, tracking etc.)
-once you know the direction of the threat try to position yourself at highest angle possible to it, 90deg is great for example as missile will have to turn a lot and loose energy while doing it, however AI is in great advantage here and I personally think TK should adjust BVR AI functions a bit, because they can evade missiles in a way you can only dream off and there's other stuff to check out...
-with above in mind you might think there's no help, but there actually is, terrain masking works flawlessly What I do is running on the deck at a razor edge of crashing into the ground and high speed then:
-pop out a bit higher wait for them to lock you up and fire missiles, hit the jammers, drop some chaff if it does not work hit the deck again, they will loose the lock, if you are persistent enough it can even happen that they spend all their BVR missiles and you have a turkey shot at them.
-remember rushing at them head on at the speed of heat will get you nowhere, AI will fire all their AHM,SAHM or IRM at you if needed, completely disregarding other planes in flight or even multiple flights! I had up to 28 missiles fired at me(you can check it out in LOG on debrief screen) and not a single one at other 7 guys in our two flights!
-Anyway 1950-1970 is really more interesting as AI shortcomings are not so obvious(game design period) and you don't expect the missiles you carry to hit anyway
But in the end, I prefer 80's, 90's so I'm stuck with what we have...