In my experience overclaiming also took place in every air force. The Japanese may have been the worst if that 400% mentioned above is a standard figure. The Luftwaffe also has a rate of about 150%, similar to Americans and British (although the Brits had a rate of about 500% during the BoB).

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„Solange man nicht mit dem Kopf unterm Arm rumläuft geht es doch noch!" Erwin Rommel