[Beck]

Like how is fleet experience determined, has anybody figured it out?

Simple. The more ships you kill, the better you get.

Actually I don't think this is entirely accurate. I haven't done a sandbox or anything, but based on my Last several games, killing ships lets you gain SHIP experience and destroying fleets is how you gain FLEET experience. It's the only thing that explains the behavior of having fleets kill hundreds of ships without gaining any fleet experience points and have a fleet have one big battle against a lot of ships garner 10+ fleet experience points. It's not tied to killing X number of ships equals a fleet experience point, but whether I kill all the ships in a single fleet. I checked my current game and I have several fleets with only 21 or 22 fleet experience points (20 of which they got training)that have a large percentage of the fleet being legendary (many maxed at 50) indicating a lot of action, but most were, IIRC, against small stacks of ships and hence would not have been fleets. This feeling is further buttressed by the behavior of several recent battles where fleets have engaged enemy stacks of 250+ ships, win the battle without being able to kill all the ships and receive one or two fleet points and have a fleet re-engage the remaining enemy ships and gain 5 or 6 points having only killed 10-15 ships. The first fleet clearly was unable to destroy very many enemy fleets while killing a lot of ships and the second was able to destroy a lot of fleets while killing only a relative handful of ships. My fleets have been engaging a lot of 150-350+ sized ship stacks and the fleet experience points received has varied from 2 to as many as 16 which again makes it appear to be dependent of the fleet makeup the AI is using or has in the stack and not on how many ships are killed.