One of the things that folks are fond of saying is that it's not the plane, it's the pilot. No doubt true to some degree, but not always.
I was watching an interview/recreation on the history channel. The subject was the introduction of the Hellcat,and the story centered around a combat between a Japanese ace and the Hellcat pilot being interviewed. The scenario goes like this:
Hellcat and Zero are fighting largely in the horizontal. The Zero has scored some hits but without great effect. At this point the Zero goes vertical. The Hellcat pilot thinks he has an absolute newbie on his hands. He goes vertical with the Zero, pulls through the arc and easily shoots the Zero down.
Turns out the Zero pilot was not a newbie at all. He was an ace with nine victories using a tried and true tactic ... against Wildcats. A Wildcat would have stalled, allowing the Zero to come over the top and hammer the now helpless airplane (remember, getting nailed by a plane with its nose pointed straight up in a full stall only happens in RoF :)).
The Zero pilot's second to last thought must have been "Where is he?". His last,of course, would be "Oh sh..!".
Sometimes it is the plane

.
Interesting discussion, Patrick.
There is a statistic (that, with my terrible memory, I've forgotten

) regarding the overall distribution of aerial victories that held true in WWI and WWII.
In both wars, when the total number of planes shot down was compared to the number of pilots getting "kills", it became clear that a surprisingly small number of pilots accounted for the majority of total kills.
Good fortune, skill, and equipment certainly all played a part... but the single factor that seemed constant with the "Aces" was
skill.
So for that small percentage of elite pilots, I think the "It's not the plane, it's the pilot" is actually true.
But yes you are right, for the "average" pilot, a lot of it really is the plane (assuming a competent combat pilot).
Especially when an aircraft first arrives in the theater, and the opposing pilots are not yet familiar with the new type's capabilities... such as the Hellcat Vs Zero example you gave.
Another example would be the arrival of the P-47 in England, when it went up against Bf-109 or Fw-190's flown by equal (or better) German pilots.
American P-47 ace Robert Johnson describes time after time the German fighters would attempt to use an escape tactic that had worked well against Spitfires, but was often a fatal mistake against a well-flown P-47: The split-s towards the deck to dive away and extend or escape.
The German fighters could usually out-roll and out-dive the Spitfire, and this escape maneuver worked in the BoB.
But the P-47 could both out-roll and out-dive the German fighters, and easily followed them through the maneuver, surprising the German pilots and often resulting in an "Oh Sh..." moment for the -109 or -190 pilot.
What was my point?

Oh yeah: I believe Saburo Sakai survived against "impossible" odds due to 1 part "luck", and 3 parts superior skill and experience (compared to the Hellcat drivers)... but in general, I'd bet on an average pilot in a great plane, over the reverse.

Best wishes.