ORIGINAL: ChezDaJez
1) "Who gets the drop on who" is almost always determined by situational awareness. Here bombers (and other large aircraft with large crews) have an inherant advantage over fighters - particularly single seaters: more eyes. Whoever spots first gets the option "engage or evade." Performance has almost no meaning here: 90% of the time whoever spots first succeeds, both offensively and defensively. Related to this, who has the situational awareness can be augmented by off platform "eyes" - including radar.
Have to disagree with you on this one, Cid. While the number of eyes scanning the skies is important, its size, profile and relative motion that matters most. A fighter pilot will nearly always spot a large bomber before the bomber crew spots the smaller fighter, especially if the fighter profile is head-on.
Situational awareness is critical to be sure. But it doesn't change the performance factors.
WWII bombers, by the very nature of their mission, must close their target to be successful. Tactical bombers may have the ability to maneuver better than say a B-17 but the fact is that they have a target to engage and will proceed to that target until it is bombed or the bombers are destroyed. Staying in formation lends the greatest chance for survivability so independent maneuver is taken out of the equation.
And the performance differential does have a huge impact here. It is the fighter with its normally large performance advantage over the bomber that will dictate the terms of the fight. It is the fighter who will choose when to engage and for how long, not the bomber. The bomber does not have the option to engage or evade.
Chez
Well - since bombers almost always flew in large formations - the point is pretty moot: how can you miss even a group of 48 B-17s? OTH, when flown in recon roles, it is closer to the 1 on 1 situation - and note that recon planes OFTEN spotted first - and the rule then applied: they could close or not. If the altitude was great enough - the risk of closing was not that great. Both 2 engine (e.g. B-25) and 4 engine (e.g. B-24 and even B-29) bombers served with distinction as recon planes, and losses were not severe in that role at all.
A fighter may also fly in formation - and in that case someone in the formation may spot what the leader has missed. Again - in large number situations - it is pretty moot. When JAAF put up a patrol line from Mid Honshu all the way to mid Kyushu - the B-29s closing had no intention of being diverted by a strewn out line of fighter planes. That there would be combat was a foregone conclusion: who spotted first was moot - both sides fully intended to close. [It didn't work out well for the B-29s, the last technical surprise of the war by the JAAF. They rarely had the fuel to do it - but when they did - they did.] JNAF came up with a variation for their late war, high performance interceptors: they put out recon planes for the fighter force - and let the recon vector them into the bombers.
In any case where the numbers are large, the targets are known, and both sides fully intend to engage, evasion is not really a factor. But these are the minority of instances of air operations. There are lots of reasons you may fly somewhere not intending to fight - not even being armed - or not in a condition where you want to fight - or not to fight what you encounter (if only that they outnumber you). Lots of things determine who gets the drop on whom - including things not on board the planes. When there are lots of planes, radar, spotters in numbers, all these things stack up to reduce the chances of being surprised. Yet another factor is training: JNAF fliers could spot at ranges up to 100 sea miles, when the target was no more visible than a first magnitude star in daylight (which, FYI, they learned to locate for practice). Normally humans do not see ANY stars in daylight - and not knowing they can - no other fighter force in history ever trained pilots to do it. Yet an aircraft is at first visible at the same level, and training to see it - and to systematically scan for such things - gave a significant advantage in the age before electronics came to dominate situational awareness.
Situational awareness is FAR more important than any performance issues: see The Ace Factor - a history of air combat by a USN fighter pilot. Not only in the sense I pointed out, for spotting first and then deciding to engage or evade, but also DURING a fight. IRL a fight is messy - and not being aware of that other guy while you focus on this guy can ruin your whole day. Yet most people find it almost impossible to be aware of the flight paths of other aircraft than the primary one they are engaged with. And even those who can are not usually able to track more than a few other aircraft. But a few pilots - less than 5% - seem never to lose track of the situation - no matter how messy. Col Robin Olds, during a fight in which he scored two kills (his third and fourth in Viet Nam - he was already an ace from previous wars) - was aware of the air combats of others in his flight some distance away. When his wingman scored he broadcast on the tactical radio immediately "nice kill that" - although it should have been above and behind him and he was chasing a plane of his own. Olds came closest to becoming an ace for USAF in Viet Nam - no other pilot scored higher than 4 (in USAF) - but he had a chance to get number five that day - and blew it off for the sake of the mission. More than a few - even outside the Air Force - regard him as more honorable for NOT taking the shot - and as likely the best US pilot of the war - never mind he did not become an ace (again). And best because he had both superb situational awareness and judgement. Note also he was too old to be a fighter pilot (like Eddie Rickenbacker in WWII - where he won his second medal of honor as a fighter pilot) - so don't make too much of that age thing. [Rickenbacker used political influence to force his way back into the cockpit. Everyone "knew" he "couldn't be any good" at his age. Everybody except Eddie, and possibly his Congressional sponsor, that is. Turned out he was superb - and it was situational awareness that made him so. The technology had changed. The need for situational awareness had not.]
Now for your final thesis: that performance is the critical factor in a fight between bombers and fighters, always giving initiative to the fighters. Actually - the bombers DO decide when to break off and head for home - or (ugly if there are fighters) come around for another go at the target. And when the bombers drop their bombs - which they CAN do WITHOUT being over their target - they become much better performers. There are lots of factors - not least of them doctrine and mission orders - neither of which is determined by aircraft performance. Do not confuse USAAF ideas with the natural order of things. Are bombers really safer in a "box" formation (which, curiously, does not look like a box at all) than they are maneuvering? The answer is - it depends on the situation. Surely it often seems like the fighters have the initiative - even if the bombers really have it. Initiative does not have to mean "I am ambushing you." And in the only battle I ever saw on land - in spite of three days knowledge of the enemy route of march - I decided the best point to engage was where we already were. It SEEMED to the enemy he had the initiative, but I really had it, because I had the choice to make it be somewhere else - and didn't exercise it. If a bomber can perform its mission, it has succeeded - whereas if it runs away without performing its mission - it has failed in the operational sense. If a bomber (or formation of bombers) elects to proceed - it may well be a proper professional choice - and not in the least an indication they don't have the initiative in the tactical sense. If they live to tell the tale, it probably was the right choice too. The opposition didn't warrant abandoning the mission.
A problem for statistical analysis of air combat is that - when a plane spots enemy aircraft and elects NOT to close and engage in combat - it is usually not classified as an air battle! Yet it is, just as surely as any other case. I repeat - and this is formal - the way they train military pilots: who sees the other guy first determines vistory the vast majority of the time. But "victory" is not the same thing as "kill." If you are a transport plane, delivering your cargo (or your empty plane) is a victory - engaging in air combat is not a good strategy for you - and if you spot an enemy fighter - or worse a flight or squadron or group of enemy fighters - or even a plane which you cannot identify (because it is too distant) where there probably are no friendly planes - you are well advised to evade. That is a victory for your side, as surely as your loss would be a defeat. Both cases should be counted as air engagements - even though the enemy never knew about it - or knew but could not catch you. It is not a dog fight that makes it an air battle - it is the possibility of air combat. [Today we often do NOT dog fight even when shots are fired - BVR combat is not a classical air engagement - but surely it is air combat.] Similarly - us plane killers on the surface count every time we COULD try something - not just firing weapons - but also countermeasures - wether or not we elect to do so - as an engagement. If you don't think this way, you won't have any statistical sense of possible outcomes when opposing forces meet.