One of the best questions I've seen around here in a long time!
You're overgeneralizing Boyd's EM Theory. The Energy Maneuverability Theory is basically the scientific and mathematical description of what fighter pilots have know for a long time - having an agile aircraft that has the power to pull off sustained maneuvers, and still maintaining the ability to accelerate and decelerate rapidly will be characteristics of the best fighter aircraft that can be designed. Remember EM Theory is based upon excess energy (the initial name Boyd gave to his theory) to maneuver the aircraft.
So, we have a concept of excess energy being used to maneuver the aircraft, we've got to plot the following in a graph:
Aircraft Velocity - V
Aircraft G -G or n
Specific Excess Power - Ps
Turn Radius
Plotting all these variables gives you an idea of where and what an aircraft can do at a specific point in it's flight envelope. These plots are called EM Diagrams, or VG or Vn Diagrams, or more generically "doghouse" plots because they look like a doghouse.
Here's one for a T-38:
From this, you can tell that the T-38 has the following parameters:
Best instantaneous corner velocity: 400Kts
Turn Rate at instantaneous: 15.5 degrees/s
Turn Radius at instantaneous: 3000ft
Best sustained corner: 450Kts
Turn Rate at sustained: 12.2 degrees/s
Turn Radius at sustained: 4600ft
Sustained would be where best to operate the aircraft since it keeps your energy high while allowing the best sustained rate of turn for your money. This equates to more snap shots in a turning engagement even with an adversary with better rate & radius but with a slower corner. Boyd would say that this excess energy would give you more options to maneuver the jet and keep the bandit off balance.
We compare jets by taking their doghouse graphs and superimposing them upon the aircraft we want to fight. This will tell us where we have the advantage vs our adversary - this is where Boyd's theory comes into real play.
As it should be! :smilewink: But I'd say that you're still a bit slow as you should be flying around sustained corner.
That's where you'd be wrong as well. I believe the Russians were well aware of the theories behind the development of the Eagle and Viper. They used Boyd's EM theory to come up with some superbly agile aircraft. Remember that the Flanker postdated the Eagle by some 20 years so they had plenty of time to come up with something that might be more maneuverable at specific points in their EM diagrams.
Boyd's theory has nothing to do with post stall maneuverability, where Cobras, Herbst maneuvers, post stall loops and mongoose maneuvers are performed. What it does is say that the aircraft that is highly agile with great acceleration, and excess power, can, in general, beat aircraft with less of these attributes - all other things being equal (the "all other things I'm talking about are pilots, of course :smartass:)
So you have Russian aircraft that can take advantage of high AOA post-stall regime, but they must be able to rapidly accelerate back to maneuvering speed.
This is one thing that's not in Boyd's theory and is called "combat cycle time." The combat cycle time is the time it takes to complete one cycle around the edges of the doghouse plot. The faster the aircraft can complete a combat cycle time compared to another aircraft (bandit), the more agile and maneuverable the aircraft.
So we have, from Boyd's EM theory, the following traits of a good fighter aircraft:
Agility - the ability to change direction and speed rapidly
Speed - the ability to accelerate, decelerate, and reaccelerate rapidly (this equates to a nice small aircraft of light mass - as opposed to behemoths like the F-4 or, arguably, the F-15) as well as making the decisions to perform specific tactical maneuvers just as rapidly
He went to further his theories by adding:
Lethality: Bringing sufficient force to bear
Precision: Employing your assets without significant error
This became his OODA loop, which is a discussion for another time.
Again, you must remember, we're still talking about the same paradigm. I just think your understanding is a little basic.