Arena Reward Inconsistency(?)

The awarded points recieved from arena seem to be quite inconsistant. For the first 100 or so fights I was recieving 10+battle# in points. I.e. for winning arena #55 Id get 65 points, and so on.

However, after having grinded up to 275ish I started paying attention to rewards and saw that I was recieving less than I should per win.

http://imgur.com/YHqqYB9,Op2PUVY

Pictures show my gains from fight #275 to fight #276 being 50 instead of 286 as expected. The fight before I only recieved 50 instead of the expected 285. Is this intentional?

Edit:
The battle after this one only gave me 50 aswell, is there a cap to it at 50? If so, that’s a real dealbreaker for me, really. If there’s a cap at how much you can earn per fight its not incentified to try to go deeper than whats “safe”, due to losing 50% of your points if you lose.
http://imgur.com/Mbm7iVD

My suggestion instead of a hardcap such as 50 is increasing it by 100 for every 100 won fights after fight #100. So you’d still get 100 for #199, but get 200 for fight #200 and so on.