Many times i've tried to find a logical explanation about the German defeat in invading Britain's mainland but the existing theories just don't fit me right.
Just think about it.
The Luftwaffe fought the RAF over the Channel and lost due to the heavy casualties suffered by the RAF (about 25% of the entire Luftwaffe strength).
Yet the RAF came to it's limits due to the ongoing battle (July- October 1940). Despite that loss, Germany managed to gather over 4 mil. troops and 4 Air Fleets (Luftlotte 1, Luftlotte 2, Luftflotte 4, Luftflotte 5) with around 4.500 aircrafts (but only about 68% of them combat ready) to invade USSR and advance rapidly deep in Soviet land.
What i don't understand is how the Germans lost the Battle of Britain and yet had enough strength to bring the USSR down to it's knees. Although the Soviets at this stage of the war were of very poor quality, the major arithmetical supremacy of the Red Army was a tough enemy to beat.
Many sources state that after the Battle of Britain the German aircraft factories didn't show much production rise maintaining the same production line levels.
So where did the conclusion came that the Battle of Britain was lost and yet the German strength was enough for invading a vast country such as the USSR?