Lots of Variables
Aciesedge:
There are a lot of variables here. A few thoughts, from my experiences, as to who the victor may be:
1. Personality: he has to be willing to take controlled, calculated risks. A pacifist won't do, nor will the guy who takes-on all opponents.
2. Numbers: in training, the fights are usually equal numbers (2 vs 2; 4 vs 4). Real combat? You would like to have overwhelming numbers. Usually, bigger numbers on your side are an advantage.
3. "Skills:" the fighter pilot who can max-perform his aircraft and its systems has an advantage. "Max-perform" means rapidly accelerating or decelerating, turning to g-limit, or aerodynamic limit, to put his aircraft in the best position to both 1) employ weapons, and 2) minimize the opponent's weapons opportunities, has an advantage. There is the "Welcome to Top Gun" scene where Tom Skerrit says "You'll fly faster than before----and more dangerous." That line is ridiculous---fighter flying isn't about faster---it's about smarter. Most traditional "dog fights" are done at relatively low speeds....but the g-load and aerodynamic load are high.
Max-performing the system means being able to rapidly move the switches, knobs, and widgets in the cockpit so as to bring ordnance to bear on the bad-guy in a fleeting moment. It means knowing which weapon is the best for the shot, at that moment.
4. Training. Part of skills. Pilots who get 3-4 sorties a week, in an unscripted environment, have an advantage. Those who fly infrequently and have scripted engagements, or are under close-control from surface radar, generally have a disadvantage.
5. Technology. It may be a great equalizer---or it may be squandered. Usually, a newer jet and/or weapons is an advantage.
6. Experience. Highly experienced pilots generally know their aircraft and its strengths and weaknesses well. They know how to employ to maximize one and minimize the other. That is generally an advantage.
7. Maintenance. A first-world country, with top-rated maintenance, will generally have a better mission-capable aircraft that a third-world country.
8. LUCK. Sometimes, all the advantages in the world don't add up. A lot of the ME-262s shot down in WWII were killed while taking off or landing by Mustangs that had the good fortune of being higher and faster to make diving passes while the ME-262s were low and slow.
9. Environment. The weather and sun makes a difference. He who gets sight first has an advantage.
10. Rules of Engagement. The guy who can shoot at anything that flies has an advantage if the other guy has to visually identify the target first.
That being said, here's how I would bet against even numbers:
A. Experienced pilot/old jet against experienced/new jet: New wins
B. Experienced pilot/old jet against new pilot/new jet: toss-up, but I'd lean towards Old guy
C. New pilot/old jet, against new pilot/new jet: New jet