Questions: How to approach a spit, Jug/Hog driver perspective.
Answer: From above.
1v1 spit above or co-alt: Extend if possible and try to return higher. The higher the alt at the start of the fight, the better. The jug closes some of the climb gap with altitude and gets a good 400-600fpm boost when 50% fuel and with the light gun package (D-25,D40) so the lighter the better as well. It is possible to stall fight a spit to some degree above 15k though still a tricky proposition. The jug can kick out flaps at 400+, it will almost hold its own in a descending defensive spiral with flaps out. In a worst case scenario against a good spit that gets the upper hand, the jug dive away and get some separation in the process. Assuming the spit follows, high speed maneuver (>450) heavily favors the jug. In a dive, jug roll is superior, G-onset is superior (the spit is much more responsive in pitch) and a descending scissors starting with a hard turn corkscrewing back into a climb will often black out the spit driver (his turn is harder since may simply pull lead for a gun solution) or even better snap his wings. If the spit stays with you he will at least now be substantially out of phase given out the advantage in a high speed ascending (maybe 45-60 deg) scissors. Drop flaps and use throttle as necessary and the out of phase spit stands a good chance of sitting in front of you albeit in a potential rope situation. If this fails and you still have >10k alt, kick the rudder in and head toward the ground again ASAP, you will need the speed to regain the roll advantage and put him out of phase as you again gain separation.
1v1 or many vs many spit below: I am much less concerned about the spit in a many v many situation even if the spit happens to be above. As the size of the engagement increases, advantage swings more toward aircraft types with snapshot capability and toughness, IE US iron. There is nothing to fear from a spit 3-5k below you in the short term. When I come across a furball the following questions go through my mind: 1. Who can kill me soonest? 2. Who is the easiest prey now? If I don't have much of an alt buffer on the cons I'm hitting then special attention does to the dora or la-7 that could eventually run me down. (Most LW U.S, birds do 343 or above on the deck, on par with the spit16) The answer to question 2 is usually "spit." The wings are horribly weak and spit drivers love to use a break turn to get out of trouble. The tail digs in and they are perpendicular to you an an instant giving an easy shot to virtually 100% of their wing area. What they fail to recognize is that by pulling too sharply they are actually decreasing the rate at which they move away from your gun solution (happens with hurris and zekes too) if you can expect it, it works like a champ. When picking on a group of spits do your best to spread out your passes between them. If you focus on one you will get fixated and not interrupt the building of E going on below you. A spit turning is not a spit extending- you've taken the energy you'd spend anyway and forced a second spit into dumping E to evade you.
In closing: The spit was made to shoot down other planes and it does it very well. It evolved as an interceptor and the LW U.S. birds show attention more to range, safety and ground pounding vice maneuver. The Hellcat would probably not have been as successful against the zeke had the engagements taken place 1v1 in a small cage but fact was the Hellcat flew en masse and did great against the zeke. If you're going to fly U.S. you're better off with a wingman than in a 1v1.
Weaknesses: Poor roll at high speeds, small clip, poor deflection shooting capability compared to most U.S. planes, lacks toughness, rapid G-onset at times, lack of combat flaps, lack of legit ground attack capability.
Strengths: Acceleration, climb, turn rate/radius.
For most MA scenarios I prefer my F6F, P47, P38 or Hog to the spit. I never flew it enough to "master" it but just enough to know what it could do. My k/d remained stable compared to flying US rides- the plane is uber when it comes to dogfight maneuvering but not uber overall due to its toughness. Unless I have a spit on my short 6, I'll take a jug any day.