I agree the problem is a very weak middle for the Allies. Have to play with the Bosporus Strait closed. Generally I like a bid of around 12-17, although I have sometimes beat my friends at 9.
A Russian fighter for the bid helps a lot, you can attack Baltic States and West Russia, and then land them in Egypt, Transjordan (with a tank) and Evenki. You get a pretty big opening, hold the Suez canal, put yourself in position to counter Japan for a single crucial turn, and lay a trap in the Caucasus while stacking W. Russia to receive British fighters. This is nice because it lets you help the British in the beginning but you end up with a Russian fighter, which is the unit which gets the most action in any game, making or breaking a lot of trades and adding a lot of defensive power. Also if you convince Germany to buy navy round 1 then you at least spare Russia through round 5.
Once you get over 15 with the bid you can start doing stupid stuff that totally changes the game… which can be very fun.