Percentage Return of footballs on adventure loot looks very wrong

I have just sent this to support as I believe the return on advs is currently not right.

Others in my guild have been discussing this too and it does seem there is a problem with the 65%/35% distribution on adv loot.

I have noticed that I have been getting very few instances of the 35% returns and tonight I have just run 14 Bastille Island adv's one after the other to see what happened. I should have got return of 34 balls 35% of runs, so approx 4 or 5 giving the higher return. Out of the 14 runs, I only got ONE which gave 34 balls. All the other 13 gave the lower figure of 20 balls.

I can understand that I may not get a 34 return if I ran 3 or 4 advs, but 14? This cannot be right!

Are others experiencing the same skewed returns?

You have misunderstood what the numbers mean. It's per server not per player.

Why would those two numbers be different though, unless there's a deliberate algorithm to ensure some players get different ratios than others!
In fact, I would assume it's calculated per adventure completion using a (pseudo-)random number generation algorithm.
I'm not even sure what "per server" would even mean - that somehow each server each has a pool of event-rewards, such that 65% of them are for the lower-value return, and 35% for the higher-value return? Even then, regardless of whether a single player does 100 adventures, or 100 players each do one, I'd expect the same result - on ~65 occasions, the player would get the lower returns and on ~35 they'd get the better returns.

Let try a simple experiment in real life. Grab a pair of dice and start throwing them. Throwing a double gives you the high reward, not throwing a double gives you the low reward. With this you would expect a high reward 16% of the time because the odds are 16%

Now start throwing to get your rewards for adventure loot and the results are pretty much as you would expect them to be.

But your also throwing to get the results of not just every battle but for the results of every fight each troop makes. Add in throws for explorer finds (more than one if you include skills), and throws for certain Geos and their skills. Now your dice are still coming up as doubles 16% of the time but what should you expect if you can see in those other areas you have been having a run of good results.

Now lets throw the elephant into the room it's one pair of dice shared by all players on the server. For all of them yes over time 16% of them will be throwing doubles for their adventure loot but just like real life most of us wont have that big win that hit the papers.

One last thought to leave you with, when it comes to loots which is your biggest income Explorers or Adventures, which of those two would you prefer to get the good loots in.

Sorry, none of that makes any sense to me. As a computer programmer I know exactly how I'd code it, and I can't think of any way I'd do so that would mean anything other than 65% of adventure runs (regardless of player/server/adventure) bring back the higher returns, and 35% the lower returns.
The only point you make that would make it different is if loot was calculated per camp or enemy units killed, but that would totally change the outcome (basically, if you only killed a single enemy unit, then you'd either get one reward with 65% chance, or the other with 35% chance. But if you killed 1000s, then you'd get some weighted average of the two possible rewards over all the battles - e.g. if it was 65% chance of getting 50 balls and 35% chance of getting 100, then you'd most likely get 67 or 68 balls, but that's definitely not what I've observed.)