I'm a Cho'Gath main and yesterday I played two games, one on Vel, one on Cho.
On Vel I completely fucked up, lost lane, went 2-6-5 but luckily still won thanks to the top laner carrying.
On Cho I carried in a 2v8 while my ADC had disconnected, top and supp trolled with the purpose of ending the game as quickly as possible (they had to go) and I went 12-3-4 with 20 stacks on Mejai most of the time (2 of the deaths happened in the last 3 minutes when there were literally 2 people playing on my team).
Got 1063 mastery points for Vel'Koz, 195 for Cho'Gath.
I know the outcome is MEANT to affect the mastery points earned, but that much?