I am wondering whether most dogfights ended decisively and if so, whether many relatively inexperienced pilots knew they were probably going to die or at least have to eject from their planes. Or was it possible for even a new fighter pilot to at least have a chance of running away rather than engaging either a better pilot or a numerically superior group of planes?
Not a conclusive answer per se, but for WWII at least:
A large fraction of fighters shot down in aerial combat weren't dogfights per se, but rather the victim being unaware of the enemy on their six before it was too late. Sorry, I don't remember the reference for this.
Clostermann, in "The Big Circus", explains that towards the end of the war (WWII, that is) on the Western front at least, the Luftwaffe became very divided capability-wise. There was a small number (maybe 10% or so) of experienced pilots, often having been in the business since the Spanish civil war, who knew their planes in and out, and the capabilities of the enemy planes as well. These pilots were extremely dangerous opponents. OTOH, the other 90% of the Luftwaffe pilots were very inexperienced, as due to fuel shortage actual training was limited and apparently a lot of time was spent on ideology instead of how to fly their planes. These were easy prey. This suggests that yes, at least during that period, dogfights were pretty one-sided.