Q: How do I increase my bonus pool? Do I have to not play?
A: Your bonus pool increases at the same rate regardless of whether or not you're playing. The rate of gain is about 1 point per 2 hours.
Q: Is the bonus pool considered in any calculations? How can that be accurate if it constantly inflates ratings?
A: Because everyone has access to the same total amount of bonus pool, it's unlikely that it is included in any matchmaking calculations.
If everyone has access to the same amount of bonus pool, what is it for then? the way i see it i can stop playing for let's say a month and go down to rank 90 in my division since everyone else kept playing, i'll have let's say 800 Bonus pool points but yet the 1st one on the division will have at least twice and more than my bonus since all the time he has been playing he still gets the same points as i do.
The way i see it since I'll have more bonus pool I can go up ranks faster yet I can't actually get an advantage of it since he got the same bonus pool but just used it before me plus the rating points he got while he didn't have bonus pool he always going to have a higher rating... so basically i go on vacation and I loose my chances to be on top of the ladder. So far I don't see a point in the bonus pool other than just making the numbers bigger... but in that case you can always go back to beta style where everyone started with 1000 rating.
It serves to separate the idle players from the active players. However, the idle players are given a chance to come back. An active mediocre player who consumes all of his bonus pool may rise above an idle pro, but when the pro returns he'll reestablish himself as king of his division. The bonus pool also serves to act as a psychological incentive to play the game, in contrast to War3's chore-like XP decay.
I don't think the system pushes you towards a 50/50 win/loss ratio It's simply a byproduct of matching you with players of equivalent MMR.
That's correct, and I apologize if that was misinterpreted, possibly poor language choice on my part. It might be better to say that the design goal
of the system is a 50% win ratio for all players. I don't want to misconstrue that as you will play against a Diamond player for every Bronze player you beat.
Do you know if there is a cap for the bonus pool? I recall it is capped at 200 pts for idle players, though I don't know if this applies to newly formed teams/players.
Blizzard has said that there will be a cap, but that the cap is large. So far, nobody has reached it yet (and it's what, around 660 right now?). The cap may also be antiquated information. It's certainly not 200.
On a serious note. Does your campaign progress or achievements factor at all into this mysterious MMR?
Absolutely not. Only your league wins/losses and the hidden MMRs and sigmas of your opponents influence your MMR.