Ok clue me in...how is getting shot in the front of the head different from getting shot in the back of the head? Other than the open casket question, in which case any head shot is likely to close the lid?
MAJOR clues...the odds, and tactics.
Sure, Boelke's Dicta preached about using many types of advantages (coming in with the sun at your back, ie.) to gain any advantage to get behind your prey for the kill shot(s)...the shot where the enemy is most vulnerable and you are least vulnerable. The highest odds of getting the kill and not getting killed are based on those tactics. If you read Manfred von Richthofen's "Der Rot Kampf Flieger" ("The Red Battle Flier"), you will see that his Mentor, Boelke, and later von Richthofen, as a squadron leader kept as close an eye on their pilots (especially rookie pilots) as well as fighting their own battles to see if they were following the teachings of the dicta...and who was getting killed by not. The odds, however, were far less in surviving a head-on vs head-on attack, as von Richthofen found out personally.
A dogfight is much like gambling. Depending on the game (aircraft), how much each person (pilot) is educated at the game (dogfighting experience), being aware of what is going on at the table (Situational Awareness), how experienced a gambler is at playing that game (pilot training)--you can come up with odds on just how risky a bet (tactical maneuver) actually is. All of Boelka's Dicta (and his later surviving commanders teachings) was an attempt to stack all available odds in their favor--as well as avoiding very high risk moves.
He also understood that the head-on was at times completely unavoidable as both an offensive and defensive move once the attack was underway as well as if one finds one self having to fight multiple attackers simultaneously. This was not so much expressed in print by von Richthofen--but more by the surviving pilots accounts after the war. Hermann Goering inherited von Richthofen's Jasta after his death and until the end of the war. von Richthoffen confided much in his brother Lothar as well as his adjutant Karl Bodenschatz.
ROX
PS--During WWII, US and Japanese pilots routinely used the HO. The US pilots believed that their planes with multiple .50 cals would give them an advantage, and the Japanese believed their 20mm's cannons gave them the advantage. In the present day, even though missle technology has taken old fashioned "dogfighting" aout of much of the equasion, they are still taught Boelke's Dicta in the classroom.