Player rating for tournaments across all installments of Heroes.

7. Separately, I want to comment on the concept of rating decay by 1/3... Have you tried calculating what will happen to your 50 rating points earned in the first stage after 10 stages? Only 0.86 points will remain... :D Why play the first stage for such a pittance? You could just play the last two and that's it...

To be honest, even I didn't get what you calculated here :) Do you mean that after playing one stage, the player will no longer participate in any of the stages?
If a player only plays HoM1 and doesn't play any others, then for the same tournament, their rating doesn't need to decay in the stages where they don't participate. However, if they skip one of the subsequent HoM1 stages, then the General rating must definitely decay. That is why I wrote that the rating decay can be sorted out as the tournament progresses.