It wasn't a random number generator issue. Every battle the magnificent German navy won had > 50% odds of winning/retreating on the attack (several of which I lost) and many of them were in the > 90% range. I had several battles on the defensive when Churchill attacked me but I never bothered to check the combat log to see if he lost any battles that he should have won. I can only assume that he didn't attack if he had < 50% odds of winning.
One tactical situatation that I used to my advantage was that the English fleet started spread out around Europe and Africa while mine was concentrated primarily in two areas. Then, Churchill split up his fleet in the
English German Channel to go submarine hunting leaving the ships that were left there a bit vulnerable. Before this English submarine-killing side mission, the kill/loss ratio was close to 50% with our navies trading blows back and forth.
Finally, the English and German fishermen were getting fed up with English destoyers running over their nets so they banded together and sunk several ships with explosives smuggled into their cargo holds.
I'm sure that there are still quite a few English destoyers, cruisers, carriers and transports still lurking around the map.
Played and sent to Hirohito-san.