First the Patch last week introduced a SERIOUS bug to the way the Dogfighting expert skill works. The bug is odd because the description listed under the skill is EXACTLY what the skill does!
"+100% to the combat effectiveness of combat fighters for each tier of difference between them."
It is key to note that this is based on the planes tier and not the CV tier.
This was supposed to be +10% to make stock planes vs. upgraded planes and lower tier vs higher tier CV not a completely lopsided fight.
However it has a vastly more extreme effect then was intended and is game breaking for CV play.
THE HOTFIX TODAY DID NOT ADDRESS THIS BUG! I have tested it in game.
Example of how this works in battle.
Player 1 is in a Tier 4 CV has stock fighters.
Player 2 is in a tier 4 CV and has the upgraded fighters.
Player 1's fighters are almost twice as powerful with the skill and CRUSH player 2's fighters kill them at a ratio of 3 or even 4 planes shot down per plane lost.
Even more extreme is the same player 1 vs player 3 where player player 3 is a CV tier higher and has fully upgraded fighters. Now player 1's fighters get a +200% increase!!!11! and the kill ratio gets even more brutal!
This bug will effect your games even if the enemy does not know about it. A fully upgraded Langley is going to win every fighter vs fighter against both the tier 5 CV they can face if that Tier 5 has upgraded fighters as well. Even 2 squads vs 1 the lower tier fighters still win.
This also effects how fast these fighters kill enemy bombers. Dropping the squadrons so fast you can kill one and then jump to another often in time to kill both. Hell you can kill the fighter squad escort AND one squad of bombers BEFORE that bomber can drop its payload and then catch another squad
There are only a few ways for you personally to minimize this bug.
1. Don't play CV, although you are still being effected as the CV battle going on over your head is still all out of wack.
2. Run stock fighters. Unfortunately if you are running stock fighters and your opponent is not then you are at least passively exploiting the bug.
3. Exploit the bug by running divisions with a Langley with stock fighters.
Finally the Mad Exploit
You get a fighter Bogue with fighter load out running stock fighters and you use the division to intentionally "fail" division and drag him up tiers and watch him clear the skies with his plus however many hundreds of % better his fighters are depending on how high you drag him. As long as you keep in mind this ability does not protect him from enemy AA and the actual carrier is kept safe. I am shocked it is not being used more widely so there must be some reason it is not happening.