I’m going to assume veterans are the ones reading this. So I won’t go into mind-numbing detail.
Let’s assume a KGF plan of UK dumping to Karelia/Archangel, and US to Algeria through the East Canada. Japan builds an early IC at French Indochina, Russia did a R1 ground build, preventing Germany from holding Karelia for any length of time, UK prevented Germany from gaining a foothold in Africa and prevented Japan from moving into the Mediterranean through the Suez. UK or US killed the German BB/transport on UK2/US2, or Germany built carrier with Libya dump with accompanying weakness vs Russia on later turns (regardless of the logistic advantage of S Eur to Balkans/Ukr dump, which is not too awful if Russia’s maintained control of WR, which it did b/c of early Allied fighters. Allied subs in Pacific harass Japan to either force destroyer build for sub hunting, or battleship escorts (both acceptable).
Pretty average game. UK builds minimal fleet protection, US builds minimal fleet protection, Japan grabs territory, Germany grabs territory. Russia drops SFE, Buryatia, Yakut, US drops China and Sinkiang, UK drops India and let’s say Australia. Germany drops Norway, Algeria, Libya, and West Russia. That’s Allies dropping 12 IPC, and Axis dropping 7 IPC. The Allies start with 96 IPC worth of territories, Axis 70. With the change in territories, that’s still 91 Allies 75 Axis. The Allies have better long term income in the midgame after control of Africa is established. You could claim New Guinea and French Madagascar for Axis, but it’s still not great for Axis.
But the Allies also have a logistic advantage in Africa. US East Canada-Algeria drops requires 2 turns after production (produced East US, march East Canada, drop to Algeria). Furthermore, it only requires 1 US transport to keep this route. Japan will have 7 units a turn at French Indochina, with an IC and 2 transports from Japan, but that already requires 2 transports. Let’s say the transports are a sunk cost; French Indochina still requires 2 dedicated transports a turn to drop to Africa; it’s only at India that you can use a single transport to drop. But India is a forward location near Caucasus, and Japan will have to do the heavy lifting in the attack against Russia. Can Japan REALLY bleed off units to Africa, with 6 US units following 6 US units every turn there, and diverting early pressure from Russia? But US is not similarly hampered. The constant chain through Africa presses on Japan’s southern reinforcement line, relieving pressure on Caucasus. That is, Japan is bleeding away from its main attack to hit Africa; US goes through Africa anyways.
So much for midgame. Allies maintain economic advantage.
How about late game? Japan pressures Kazakh/Novosibirsk, and Russia collapses at Caucasus, Belorussia, and West Russia. That’s 12 IPCs more to Axis, say 13 with Evenki. But just what are the Allies doing all this time? Either UK should have started rolling Germany up from Karelia, or US and UK should be hitting W Europe with 11 / 8 units (8 ground plus 3 air from London, 6 ground plus 3 air from East Canada, with 3 US transports at East Canada and 3 US transports at Western Europe maintaining a steady reinforcement stream) - becoming 11/11 pretty quickly. Or maybe US is just ramming 10 units a turn in through Persia, or US is grabbing Pacific islands. Anyways, the outcome is still contestable.
How about endgame? Moscow can fall, so long as Berlin follows. With Russia and Germany both fallen, Allies typically have the advantage. Japan will have a lot of units, but can only produce 12 units a turn at Moscow and Caucasus. UK/US can produce at Berlin and Southern Europe for 16, and use transports for another 16. Even then, Allies have a huge logistic advantage in Atlantic with ability to drop infantry almost anywhere on coast, which Japan cannot do. Japan will really need a huge unit advantage to overwhelm Berlin or Southern Europe before the Allies can stop it - but it should not be able to do this, since the Allies should have at least 3-4 turns to build reinforcements (assuming Allied blocking of Jap forces); with the logistic setup from Allies, 3 turns means 48 Allied units just from transports alone, let alone production at Berlin and Southern Europe.
So put it all together. Allies have economic advantage early game. Allies have economic advantage midgame. Late game, Allies might not have economic advantage, but they may, and they will definitely have a logistic advantage. Plus, they can afford to lose Moscow, while the Axis can probably not afford to lose Berlin. So it comes down to, how much earlier will Moscow fall than Berlin? If Moscow falls a lot earlier, Japan can race in to save the day. If not, it can’t.
But regardless, the longer the game goes on, the better the chances the Allies have.