I think there were several possible alternatives that lead to a Central Powers victory. The most obvious is keeping the US out of the war. The unconditional submarine warfare did not cripple Britain and it is unclear to me that Wilson would have gone to war if the German navy had called off the North Atlantic campaign. Second would have been if Italy had honored its treaty obligations and joined the Central Powers. While the Italian Army was not particularly successful they would have forced the French to defend their southern border. I am not sure about the race to the sea. I don't think it is realistic to assume either side could have moved fast enough to flank the other. Finally what if the Germans had not invaded Belgium but merely launched probing attacks against the French while concentrating in the East. Balfour went to war to protect Belgium. Had Britain been neutral teh French Navy would have had a problem establishing an effective blockade.
