One versus many is often the only fun fight available in the MA as so many players fly so timid/smart (delete to taste). Its fun to watch the mentality of opponents switch from fear to greed as they gain a numbers edge. This can sometimes be their undoing....

The F6F-5 is a great plane in this sort of fight. It is heavy but has the most wing area of any single engined fighter, plus great flaps. It can crank its nose round surprisingly quickly and is often underestimated by Spits and other turnfighters.
As others have said the trick in this sort of fight is to force overshoots. The flaps and excellent rudder slow the Hellcat up quickly and it can maintain control at very low speeds where other fighters are spinning out. You can often sucker one or two guys into a scissors fight while avoiding the faster opponents.
You need to take any deflection shot you get when outnumbered, a straight six shot makes you too much of a target. Luckily the Hellcat has a great view over the nose if you raise the seat position and very accurate guns with lots of ammo.
You are likely to take damage in this sort of fight but the Hellcat is tough enough to absorb a lot of punishment.