Japan needs to take out US NO money in the islands, Brit money in the Far East, and then turn attention to USSR. This is true regardless of what the US does IMO, but its FAR easier if the US ignores the Pacific and goes with KGF or KIF (in which case Japan should add nuisance raids against Alaska and the West Coast to her list of tasks). As soon as the Japanese player suspects the US is not playing in the Pacific (generally by J2, but a good US player can disguise it for maybe one more turn) they should drop an IC in Asia (more when you have India) and commence building Tanks there and Bombers in Japan. Japanese Bombers can get into action against the USSR pretty quickly and then the Tanks follow up.
Also its important for Germany and Italy to understand what is happening. If the Allies are going with KGF (a bad idea IMO), the goal is simply to survive. They need to pressure Russia and try and retain NOs, but there is no need to push on heavily towards Moscow. Japan will be there soon enough and if the Japanese player is any good at all, the econ will be favoring the Axis, not the Allies. Time will be on your side.
Finally, the Axis need to coordinate their efforts and timing. If Russia is the target, then Germany needs to be hitting in the North while Japan bombs and moves in the from the East while Italy threatens the South. If you let Russia respond to each in turn, its far easier than when all 3 are happening simultaneously! Ditto for fighting England. The quickest way for England to go down the tubes is for Japan to be taking the Far East (and/or Mid East and eastern parts of Africa), Italy to be fighting for North Africa, and Germany to be attriting Brit boats with air attacks. Brit money will drop fast and her ability to replace losses will go downhill fast.
We’ve seen about 50/50 Allied/Axis wins. Usually its simply stronger play (or occasionally better luck) that determines the winner. I have yet to see anything definative that would make me think that one side has an advantage yet.