Here is the "secret":
At the start of the tour, first simply do a few bombing raids with a B24 and the 4/2000lb bombs to a city... drop as many buildings as you can with each indiidual bombs. Do this about 5-8 times and get a %12 or better bombing % with no deaths, and couple that with a single C47 base capture and you have just secured yourself in the top 50 bombign ranks. Secondly, take up a 190A-8 in fighter mode for a few flights and attack nothing but flights of bombers. Score no more in the bombing category. After 15-20 sorties you should have a 5 to 1 or better kill to death ratio. Obviously, the more kills and fewer deaths you have the better. You'll have secured a rank well below 200. Thirdly, with the GV scoring you MUST do three things: First, get a base capture using an M3, 251, or Jeep. Second, use the 251 or PT boat and rockets vs a strat target. Third, have at minimum a 1 to 1 kill/death ratio in both ground to ground (gv to gv) and gournd to air (gv to aircraft). If you do that you will probably get well below a 200 rank score in gv's. Easy stuff.
Then, to preserve those scores all you simply have to do is to avoid scoring ANYTHING in fighter or bomber mode and instead simply score everything in "attack" mode. Obviously, he more kills to deaths you have the better but I've had a 1 to 2 kill to death ratio in attack mode before and scored below 200... so take it for what it is worth.
I am at best an average "skill" level player. Yet, in less than a year I'm scoring as high as 44th and I'm doing so with Mossie's, P40E's, 109F-4/G-2, Spit 9's, and other 20+ ENY aircraft. Just keep in mind that the "scoring/ranking" has little bearing on actual skill. It is more about the point watchers than anything. This tour I'm have more fun, getting more done, and have peeked at the my rank just a few times (last rank was in the 200's).
Like many things in AH2... the scoring is inconsistant, it is outdated, and it is ignored by the programmers/coders/HTC. it isnt rocket science and there re multiple fixes that could be applied with very little coding. It is as it always was (or so I have been told) and like many legit and simple things that have been brought up by numerous subscribers... the odds of it being changed is none and non-existant. Just because things are the way they are now, or they are they way they have always been does NOT make it the most efficient, legit, or accurate manner in doing something.
One has to wonder why HTC displays no motivation to test out new scoring methods (or other game issues) from time to time.