I'm going to be short and simple:
Keeping best 10 of last 14 rounds it's ok for hacks and amateurs. Once you're promoted to pro, the number of rounds that build your avg. should be increased (15/18 for example). And even more one you're a master (24/26 for ex.). If the new legend/elite/peoplewhousuallyshoot20'sand50's tier is released, 30/30 would be nice lol.
Why? It would show a more true avg., not just a "how well i've played last 2 days" and avg. wouldn't jump from 61 to 58 in 2 good rounds.
It's something that i had in my mind and wanted to share.... :)
To avoid sandbagging, i'd introduce a second way to promote from one tier to another. For example, when a pro has X (15?) rounds of 32/64 or under he automatically becomes master.
Well, that's all, any thoughts/ideas are welcome ;)