I don't put much weight on victory tallies or claims either which means inevitably kill ratios are also flawed. Some attempt to make assessments of the relative abilities of aircraft based on kill ratios which are therefore not only based on a deeply flawed set of statistics, but also fail to take into account the myriad of other factors which can effect the outcomes of aerial combats.
In the early stages of the war pilot claims were taken very seriously and used as a basis for intelligence assessments. By late 1940 both the British and the Germans, who both also had fairly rigorous systems, were realising just how unreliable the data were.
When the USAAF entered the fray in Europe the different systems for verifying claims caused some friction between the allies. Here's an interesting correspondence to illustrate how:
A reassuring result, emphasising that the Americans had mended their ways and adopted a more rigorous system:
Cheers
Steve
Those documents neglect to mention that the RAF was every bit as guilty.
31st December 1941
" At year's end, the JG 26 scoreboard for the war to date heavily favored the Schlageter pilots: 916 victory claims had been confirmed (out of about 1,000 submitted) in exchange for ninety-five pilots killed in combat, twenty-two killed in flying accidents, and thirty-four taken prisoner.
Across the Channel, the end of 1941 found Fighter Command at a new peak in strength, controlling an even one hundred squadrons. But the new war in the Pacific, and the galling fact that the true victory/loss ratio for the previous six months was well in the Luftwaffe's favor, compelled the war cabinet to warn that a more defensive policy was now a "disagreeable necessity". The brakes were applied to the non-stop offensive.
The Schlageter fighters, and the Richtofen Geschwader to their west, had totally disrupted the British air strategy for 1941. Between 14 June and 31 December, Fighter Command lost 411 fighters over the Channel and the Continent, while claiming the destruction of 731 Luftwaffe fighters. The true loss to the Germans was only 103 fighters.
In all of 1941, JG 26 lost forty-seven pilots killed in combat, seventeen killed in accidents, and three taken prisoner. These casualties, while serious, were certainly sustainable. FW 190A-2s were now beginning to arrive for the re-equipment of the Geschwaderstab and the First Gruppe. The experienced fighter pilots of the Schlageter Geschwader were confident that in the new year their Focke-Wulfs would further increase the German margin of superiority."
31st May 1942
" A Fighter Command intelligence appreciation dated 19 June claimed that 205 Luftwaffe fighters had been destroyed between 1 January and 31 May for the loss of 242 Royal Air Force fighters. The true picture was much bleaker for the Allies. During this period the combat losses of the two Kanalgeschwader totalled only sixty-seven fighters and forty-seven pilots; the fighter loss ratio was 3.6:1 in the Germans' favor."
See Don Caldwell,
The JG 26 War Diary: 1939-1942, p.198-199, p.244
What happened on 9th August 1941 is a shining example. The box score in John Foreman's
Fighter Command War Diaries shows an outrageous number of victory claims by the RAF: 22 German aircraft destroyed, 11 probably destroyed, and 7 damaged. The majority were claimed during the main event, Circus No. 68. Such big names as Victor Beamish, Jamie Rankin, Alan Deere, Johnnie Johnson, Bluey Truscott, and Paddy Finucane inflated their scores. When Douglas Bader returned from the German PoW camps, he claimed to have shot down two Me 109s on his last mission. At the time, all of this was accepted at face value.
In his book
Bader's Last Flight, Andy Saunders finds that the Luftwaffe lost just one aircraft in these combats. The author concluded that Messerschmitt Bf-109F, Works Number 8350, was probably shot down by Nip Heppell of No. 616 Squadron, who noted correctly that the German pilot suffered a parachute failure.
Saunders also points to convincing testimony in the after-action reports that three Spitfires were shot down in error by RAF pilots, due to faulty aircraft identification. The victims were Christopher Chapman, Justin O'Byrne, and Douglas Bader.
Likewise on 13th October 1941, John Foreman's
Fighter Command War Diaries records that RAF fighters claimed 22 German aircraft destroyed, 3 probably destroyed, and 18 damaged. The only known German loss is one Bf-109F, Works Number 8288, that was shot down by return fire from a Blenheim bomber.