This is a single player tactic. I have not yet tried it in multiplayer, but I admit it will probably not work. It has worked for me seven times in a row and the quickest I have achieved victory is December 1942. Most commonly I win between April 1943 and June 1943, just before the US major offensive capacity arrives.
This is a bit gamey but it is all about the concept of throwing what you have at the enemy in the best way possible in hopes of throwing them off balance long enough to win. That's how I win strategy games. (Well, I say win...)
What this strategy dictates is a measured defensive thrust into Southeast Asia to secure your fuel with a
simultaenous thrust into the Sea Lanes to secure Espiritu Santo and hold it for the allotted time.
What I mean by a measured attack is that you do what you have calculated is the minimum required not to run out of fuel. A fuel surplus is not, I repeat not, necessary. I have won with only two months left of fuel before. I never capture Leyte or Java. At some point or another - when the time it takes to win via sea lanes is less than the time it takes to lose from fuel, you transfer all your forces from defending fuel to defending Espiritu Santo. Your spare SNLF will be going into attacking Wake/Aleutians to stop them attacking your home ports, and into severing the actual game link between Brisbane and West Coast.
Expect high losses! You must sacrifice to gain strategic objectives.
In all the games I play, there are only four places where ships are lost;
-Hawaii
-Home Islands
-Singapore
-Espiritu Santo
So this is a concentrated offensive. I am typing this as I play it (yay for windowed mode.) It begins as such...
December 1941:
Kwajalein Port; Tatsuta, Tenryu, SNLF-3 attacks Wake. Move forces from Truk to Home Islands. Marianas Is. forces attack Rabaul. Add Zuiho and Hosho to Striking Force and raid Hawaii. Kongo, Haruna, and 2 CAs attack Luzon, the rest of the Formosa garrison move to patrol Home Islands.
Results: 4 BBs sunk at Pearl, Luzon captured, Wake captured, Rabaul captured. No losses.
January 1942:
1 SNLF from Home Islands, plus
all the IJN BBs attached to Striking Force and set to attack Singapore. Shoho, 3 CAs, + SNLF attacks Guadalcanal. Convoy goes to Rabaul. The forces that attacked Luzon, redeploy to Rabaul.
Results: Guadalcanal captured. Singapore captured. No losses.
February 1942:
The force that just attacked Singapore has rebased to Formosa. This patrols Singapore. Yamato + CL/CAs attacks Borneo. All forces in the South Seas attack Espiritu Santo with 1 SNLF from Home Islands. Convoy goes to Singapore.
Results: Borneo captured. Espiritu Santo captured. Americans attack Singapore;
Nevada sunk, Saratoga/Enterprise sunk. Oil situation now stable.
March 1942:
Convoy goes to Espiritu Santo. Forces at Singapore maintain patrol of Singapore, all other forces redirected to patrol Espiritu Santo. Some CAs attack Aleutians.
Results: US CV at Aleutians. I retreat :P
April 1942:
Convoy goes to Espiritu Santo. I try Aleutians attack again.
Results: Americans raid Home Islands. I capture Aleutians.
May 1942: Sea Lanes cut! 5 months left! I attack Tarawa and Midway. Continue patrol patterns, although divert Shokaku and Kaga, Yamato and Hiei to patrol Espiritu Santo. Convoy goes to Espiritu Santo.
Results: Withdrew from Midway, Tarawa captured.
June 1942: Some repositioning. Convoy goes to Espiritu Santo.
Results: No combat.
July 1942: Three months left of Sea Lanes, so I redivert my ships patrolling Singapore to patrol Espiritu Santo. Which is basically my entire Navy. Convoy goes to Espiritu Santo. I attack Hollandia with some CAs as I am bored and have SNLF surplus.
Results: Hollandia captured, obviously.
August 1942: Two months left of Sea Lanes. Bored so I attack Midway. Convoy to Espiritu Santo.
Results: Midway is mine.
September 1942: One month left. Leaving some CVL and CA to defend Espiritu, I launch a gigantic raid on the US Fleet at West Coast. Convoy goes to Espiritu Santo.
Results: I discover that there are eight amphibs lying around doing nothing in West Coast.
I win! I have lost no ships
[SS]. The allies have lost 2 CVs, 5 BBs, 1 CA, and 3 CLs. This strategy is ridiculously easy and after playing this game, I do believe it is bugged/shows an imbalance. Or maybe it was just this battle - in other games I have lost most of my ships and still won. I had the strength to bleed the allies on the defensive for six months there, it was just lucky I didn't have to. Unsure whether this is truly imbalanced since I have not played in multiplayer as it does not work. If it was MP I would be less slack.