When Gregory Cochran mentioned The Wizard War, he cited a classically thick problem that R.V. Jones solved with his personal filing system. From page 323 of my copy:

At the same time, as my memorandum to Inglis had stressed, there was much to be said for using as few individuals as possible, and stretching them to their utmost.

It has been part of our policy to keep the staff to its smallest possible limits consistent with safety, because the larger the field any one man can cover, the more chance there is of those fortunate correlations which only occur when one brain and one memory can connect two or more remotely gathered facts. Moreover, a large staff generally requires so much administration that its head has little chance of real work himself, and he cannot therefore speak with that certainty which arises only from intimate contact with the facts.

It was an encouraging experience to find just how much a few individuals can do, and how even a single individual can sometimes be more effective than a large organization. During the Battle of the Beams in 1940 and 1941, I myself read every Enigma message. A full record of such messages came to me daily from Bletchley, and in the early days they were typed on different typewriters, or sometimes the same typewriter with different ribbons or different carbons. I could usually remember the date on which a message had been received, the colour of the carbon copy, and its degree of blurring along with the part of the page on which the message had been typed. It was therefore usually a matter of seconds for me to flip through the file and pick out a particular message, even two months later. After I had done this a number of times over the telephone in discussion with Norman he had said enthusiastically, ‘You must have a marvellous filing system! We have an enormous one here, and yet we can never find a message as fast as you can. Can we come up and see your system some time?’ I told him that I should be delighted to show him and his colleagues, but it was hardly worth their making a special trip.

Norman’s honest surprise when he found that the index was in my head was one thing; but the suspicions of others were less easy to deal with. The information must have been churning continuously around in my head, only returning to the conscious when some hitherto unseen correlation presented itself. The effect of producing theses correlations out of the head, if not out of the hat, was to lead some of our associates to think that I had a great source of information that I never revealed to anybody outside.

There were at least three attempts made to infiltrate liaison officers into my Section to locate this great undisclosed source. In one, an officer from Bletchley was offered to me on a part-time basis to help but, as he told Norman and me afterwards, his main task was to uncover my mysterious source. After a month or so, he was called back and asked what he had found. He assured his seniors at Bletchley that there was no trace of anything other than what they already knew. When someone asked, ‘Then how does Jones do it?’ Bob Pryor, the officer concerned replied, ‘Well, I suppose, Sir, he thinks!’ Another officer who had been infiltrated became so enthusiastic as to have defended me to an Air Commodore who told him that I was a funny chap, and that he, the Air Commodore, had not been able to get on with me. ‘Well Sir,’ was the reply — and it came from a Flight Lieutenant — ‘You must remember, he doesn’t suffer fools gladly!’