I have attempted Japan attacks at all phases of the game with multiple attempts against multiple players. The best return for Japan, against players over average or greater skill than I, is to attack either on Round 4 or on Round 3. (Either way, that makes it the latest for America to collect their NOs and thus, puts America at the weakest possible part of the game.)
The DEI is worth a great sum of money. If you can entire England to violate the neutrality with you, it would be easier to get DEI (since you are now permitted to bombard the limies right off the map.) If they do not, the fallout from attacking early far out-weighs the gain. Hence, as most Brits won’t attack you, the earliest you can possibly get DEI is round 4, and only if you have yourself set up for an immediate attack on those four nations. Granted, America is most likely piled into Hawaii/Aleutians ready to nail Japan/Korea by this point, so you have minimal transport defenses at best if you are down there. Hence, it’s very hard if not impossible to get DEI and hold it for any period of time. (American players seem to enjoy Hawaii/Aleutians, and with good reason, you have to keep ships up by Japan which means less down by Australia so in effect, you’re being stretched too thin.)
I also build with about half my income at the very least in naval units. If you don’t put ground units in, you won’t be able to keep China/England ground forces subdued, so it’s really a catch-22.
As for your assertion Frank, to break the back of Japan means to stop any expansion by Japan and be in a position to start sniping away Japanese NOs. Generally speaking, GOOD players are at this point by round 4 (start of Round 4) average to mediocre players are at this point by round 6, bad players may get to this point by round 8, but who cares what bad players do?
Here’s how most games go down, from what I have seen and participated in:
1) Russia and England turtle and eliminate the Italian pressence in Africa. This is actually pretty easy since the British fleet is in prime position to sink over half the Italians with inconsequential losses - it is even better if you can get a German plane or two while you’re at it. Russia lines the German border with mass units. As Germany gets stronger, Russia retreats into their reinforcements and steals into Scandinavia. Italy, being unable to add reinforcements, is gone from Africa. A simple shuffle of troops from S. Africa to Egypt should handle that, more so if Germany does not look to be setting up for an attack on London, since you can then put down a complex in Egypt and kick them out faster. Fighters from India may assist if needed as they can easily fly back to India.
2) Japan invades deeper into China, but since England cannot really be attacked (it can, but it’s suicide) they cannot get any of their NOs except the FIC one.
3) America puts out huge hordes of ships every round (6 a round can go directly into the Pacific with a minor complex in Mexico - the rest off the coast of E. USA to sail to W. USA which is a short trip.) Eventually, by round 4, America’s fleet is too massive to be sunk, not strong enough to sink the Japanese one. By round 6, the American fleet is not only too massive to sink, but can swat the Japanese fleet aside crushing it and keeping all of their capitol warships at a minimum. By round 8, Japan is land-locked, essentially, with what ships they have in SZ 6 protecting against invasion while Australia and India pick off islands reducing Japanese income.
4) America starts building in the Atlantic. Now that Japan is no longer any kind of threat, America can focus on saving Russia. Now Germany faces the ungodly income of the Americans and are stalematted in Russia. It is only a matter of time now, with English forces pooring in through S. Africa, American forces transport trained into Scandinavia and down through North Russia and/or Landing in Europe directly, the game is over.
How did it all come about? Because America is way too strong at this point in time. Japan either needs a buff so that they can counter a full American investment in the Pacific or America needs a penalty for investing too heavily in either theater. Remember, Russia and England do not have to win, they just have to stop the allies from losing, that is significantly more easy! With 52 IPC * 3 Rounds + 72 IPC for 2 rounds + 80 IPC for one round (gets you to end, round 6) America will have invested an extra 380 IPC into naval units to crush Japan. Add to that the 129 in naval units they start with and the 83 IPC in air power they start with, you have a combined attack force worth 592 IPC. Against that, you have Japan with 177 IPC in naval units at the start + 212 in Air power and only (given the benefit of the doubt here) 44 IPC a round income, the MOST you can have against America is 653 IPC in navy. That may sound like enough, after all, one generally budgets to have 150% the attack punch of the defender, right? But here’s the kicker, that Japanese number assumes no losses to your ships or aircraft and assumes no investment of ground units into China. Essentially, that assumes China rolls over and plays dead, not attacking or building to counter you, and that just isn’t going to happen. More realistically, Japan is going to have to invest about half their pay into destroying China, so drop that 44 IPC a round (best possible income, remember) to a more realistic 22 IPC a round and you get a more accurate picture: 521 IPC in units and most of those are planes so you will have to buy a lot of carriers to hold them all, or they no longer count and carriers have no attack value, so your punch goes down from there. It is probably safe to say 3 aircraft from scrambling, and you probably have 4-6 in China helping there, so let’s drop 3 fighters and 2 tactical bombers from that list of Japanese units to defend against America, reducing Japan further to 469 IPC, including the strategic bombers which you won’t have on defense, so that goes down to 445 IPC defense vs 653 IPC offense.
So you have 653 IPC in gear attacking Japan (less transports 3x = 21 IPC, reducing to 632 IPC) vs 521 IPC in gear defending (includes scrambled fighters from one Airbase). That is 1.21 to 1 in America’s favor. America would GLADLY take that any day of the week. Even if you assume America loses the battle, there cannot be much of anything left of the Japanese fleet, certainly not enough to counter the Australians who are coming in for a second raid with a few destroyers and a cruiser if all there are for Japan are a scattering of damaged battleships.
Now you are left with Japan earning 44 IPC and America earning 80 IPC. Who is going to rebuild faster? Yea. Even assuming you got great dice and were able to sink all the Americans (and that just isn’t really going to happen, not often anyway, it might on an off day with the dice) you’ll never be able to press it for an advantage and America will. Either way, your days are numbered. Most likely, you are now taking CRD to Japan, England and Australia are landing reinforcements into China on a regular basis, Russia may start sending some tanks in as well to push the Japanese off the mainland faster (so you give them 12 IPC, they are unable to use it effectively anyway!) and America starts building carriers and transports to land troops in England/N. Africa and start threatening Germany’s soft under belly.