All good advice from the other posters.
I think the key to better K/D and higher Rank, is killing your target quickly. Everyone talks about Situational Awareness, but in AH it can change very quickly. What looks like a 2 v 2 now will be a 3 v 1 in 30 seconds, the bandit you're not chasing kills your countryman while you chase that spitfire around in circles. If you could have dispatched the Spit on the first pass, it's now a 2 v 1 in your favor. you help your countryman, and now when that next bandit shows up you have the advantage. this is why the better sticks have success. Their quick kills change the dynamics of the fight.
Shooting is the key. Learn to make one shot kills. You have to be able to predict the bandit’s first evasive move and time your first shot perfectly. If you can kill what you shoot at, you won't fear furballs or even being out numbered. If you’re taking 6 bursts to kill a bandit, you'll probably not be much better than 1:1. You'll get the kill, but die shortly after.
Making one shot kills takes good aim, good timing, and the proper gun package. AH rewards two things; Cannons, and putting all your rounds in the same place. Most American planes suffer from having .50 cals and having them spread over the length of the wings. At anything but the perfect convergence settings your bullets spread out all over the bandit causing you to have to hit him for longer periods of time to get a kill. This means you have to set up your approaches to the bandit in such a way as to turn with them for a few seconds. That limits the various approaches that will be successful. Pony pilots will often wound a lot of bandits but are wise to not stay with him to finish him off. I call the Pony B “The Assist Generator.” Good flyers of American planes know how to set up the shot, anticipate the break, time the shot, fire when the convergence right, and aim so the bullets cut a nice slice across one wing. The other thing that you have to pay attention to in planes with wing mounted guns is getting your lift vector parallel to the bandit’s lift vector. Because the guns spray pattern is a horizontal flat line, if the bandit rolls out of plane, many of the bullets won't hit him. All of that is why it’s harder to get quick kills is wing mounted, machine gun planes. The biggest threat to an attacking Pony is the bandit he just shot at, because he probably hit him, but didn’t kill him. And why so many pony drivers have a reputation for fighting cautiously, and Picking.
The exception on American side is the P-38. It has a cannon, and the 4 machine guns are in the nose, essentially co-axial with the cannon. Without any real convergence required, all your bullets will hit the bandit in the same place. P-38 pilots can kill bandits from all angles, and at all closing speeds. It also has a ton of ammo, and why so many can be real killers in the Lightning. Here is my ranking of how often (in percent) the plane’s gun packages kill on the first burst (assuming you hit him).
One Hit Wonders:
Great (90%) 109-K4, 109-G14(30mm), Me-262, bf-110, me-410, FW-190-A8(30mm), Ta-152,
Excellent (75%) N1K2, FW190-A5, Hurricane, Tempest, F4U-C, P-38, La7, A-20
Mediocre (50%) Spitfire, Seafire, P-47, Pony D, F6F, F4U, A6M, C205, C202, P-40, Fw-190D, Ki-84, Ki-61
Lousy (20%) Pony B, P-39, FM2, Brewster
If you can master the “first burst” kill, then your K/D will increase dramatically. It’s really what to focus on first. People will say S.A. is what to focus on first, but if you can’t shoot, no strategy will make you effective. Pick a great or excellent “One Hit Wonder” from the list and get good at putting rounds on the bandit.
Good luck
Vinkman