I just saw that top alliance ‘head hunters RU’ has 82k in titan score.
How is it possible since you loose 5% per day and win max 4000 (10*x400) the Max should be 80k, no ?
Decay takes it back to earth.
Paper theoretical limit pre-decay is 84k (little less than that actually with the mechanics, but it’s an upper bound even if it never gets there mathematically); however, if you’re really quick you can kill two titans before the decay time so could see up to 88k as an upper bound but this isn’t particularly common and it’ll probably go back to not possible once 1.9 drops for everyone… I’m not in a rush to update just sayin’ 
80k is the upper bound for post-decay scoring as you’ve described.