Would Japan, paradoxical as it may seem, have had a better chance to defeat the Americans, if they had drifted into war without an attack on Pearl Harbour ? In immediate terms, it would have freed up between 2 and 4 aircraft carriers (two might have needed to be based on Truk or somewhere to counter potential US naval moves, another one or two perhaps needed to remain in home waters for the same reason). But in strategic terms, might not the survival of an intact US battleline have led to a more battleship-orientated thought process for the Americans, and thus removed something of the advantage that came by being forced to develop the carrier taskforce out of necessity ?
Presumably, Hector C Bywater's "1931 - The Great Pacific War" offers some idea of what the US strategy would be. If we assume that the Japanese, other than Pearl Harbour, continue OTL plans elsewhere, then the US strategy would be fixed upon defending the Philippines. At Pearl in December 1941 are two carriers (Enterprise and Lexington) with another joining them (Saratoga). Using these carriers as the Japanese used their light ones in the initial attacks (i.e. to cover the battleline, and attack coastal installations). US thinking would remain focused on the potential battleship-versus-battleship clash ahead, with the carriers presumed to be in a support role.
Japanese submarine strategy was to use them to support the combined fleet - thus, for once, the US plans to come West would play into Japanese submariners hands. Since Japan is the one preparing for war, it would also have time to establish picket lines of submarines, and patrols in areas the US Pacific Fleet is going to need to come through.
It of course needs to be remembered that no one assumed that some of the Allied installations could fall as quickly as they did, so US reaction to the outbreak of war is not going to be panicked. It might thus not be until about the 20th December (allowing time for Saratoga's arrival and replenishment) that the US fleet sorties from Pearl. It may even be later, depending on US reactions to news of the invasion of the Philippines
The question, I suppose, is can Japan win at sea in this scenario ? If the US carriers are used as adjuncts to their battleline, can a similar Japanese response result in sufficient success that the balance of forces over OTL is improved in their favour ?
And having fought their fleet as a battleship-first formation, would not the US, even after its mauling, continue to think in these terms and reinforce Pearl with battleships as a priority, thus prolonging this method of thinking ?
Best Regards
Grey Wolf