Ultra and BoB

I have seen it said that it was of great use but this post on the Axis History board says it was not of much use for RAF FC for operations for intercepting the German raids.

"I do know from going through the HW files at Kew that the amount and timeliness of the information coming from ULTRA in 1940 were extemely limited, albeit most of it was Luftwaffe traffic. The information that was being obtained was valuable only for order of battle information (basing, serviceability, and crew strengths for some Luftwaffe units) and very, very rarely for operational information."

The poster works at the Dupuy Institute.

Al: A good book that takes Ultra into consideration is "Bodyguard of Lies"
by Anthony C. Brown. It's two volumes, and I just finished it. Ultra played
a big part in the decisions made by the "big wheels" in WW-II. For instance
Ultra revealed all the details on the raid on Coventry that anyone would have
needed to evacuate or to meet the threat. Churchill was afraid if he did
something to neutralize the raid, the word would get out that Ultra has been
compromised.... that he wouldn't chance.

Ultra did play a part in the LW raids, but just how big is anyone guess.

Charles