[Graham Boak]

I have long felt that Doolittle's "freeing the fighters" rule was only possible because of the increase in the numbers of fighters available. Groups could go "freehunting" because others were available to stay with the bombers. Unescorted bomber groups suffered.

There's a similar logic in the Atlantic convoy battles. Success came to the Killer groups that went away to fight the U-boats, but they could only do that because there were enough other escorts to stay with the convoy. That and the code-breaking successes that told them where to go to find the U-boats, but I can't find an analogue to that in the air battles!