First, let's take a look at the Bonus Pool.
Q: Is the Bonus Pool accumulation rate different in Heart of the Swarm?
A: Yes. It's now 180 per week for Master/Grandmaster, 104.4 per week for lower leagues, 66% of the normal rate for Arranged 2v2, and 33% of the normal rate for Arranged 3v3/4v4.
Q: Blizzard said the Bonus Pool will be consumed twice as fast now, what does that mean?
A: The Bonus Pool now not only doubles your earned points for wins, but any points you would have lost due to losing a game are now absorbed by your Bonus Pool as well.
Q: Doesn't this make it harder to reach the top of a division?
A: No. Your Bonus Pool is still practically a decay mechanism. Functionally, the Bonus Pool is still just unrealized points. It's just easier to spend 30 Bonus Pool by going 10+10, -10+10, 10+10 than going 10+10, -10, 10+10, -10, 10+10. The end result is you still end up with 40 points, it just takes less games.
Unranked play is a new addition to Starcraft II HotS and WoL 2.0.4. There are a number of Blizzard posts scattered about which explain it, but they only go into so much detail. I'm still fielding a lot of questions about what exactly Unranked is and what its effect is on the ladder as a whole. Below I'll cover some of the more basic questions as well as some speculation as to the impact that this new feature has on Ranked play.
Q: What is Unranked Play?
A: Unranked is functionally the same thing as Ranked play. It uses the same automatic matchmaking system and the same rules for matching players. The only difference is that you aren't assigned a league or division and you don't earn or lose points for Unranked play. You also don't carry a bonus pool.
Q: How does the matchmaker pair me with players when I queue Unranked?
A: You already know that matchmaking works by finding players of similar hidden MMR. If you have no prior history (primer: if you have to play 5 placement matches instead of one, the matchmaker has no prior history for you meaning your MMR returns to the default starting value around the middle of the ladder), then you inherit the MMR from your pre-existing value. For example, if I'm Gold in Ranked and I play my first Unranked match, I'll be starting Unranked from Gold. After the first match, the MMRs can diverge and will remain separate. Your next Ranked game will have no impact on your newly-established Unranked MMR, and vice versa.
For most players, this will be a one-way transition from using Ranked data to establish an Unranked MMR. However, technically it does work the other way around as well, just something to keep in mind.
Q: How can you tell which games were Unranked in a player's match history?
A: This can be quite tricky. There's a lot more research involved now.
1. Unranked games don't award any points, that's the first thing to watch for.
2. The next thing is to find out whether a game was a Placement Match or not, and usually you will find this out based on the number of placement matches leading up to that game type. If a player has any remaining Placement Matches in his profile, there's no way to know for sure. If he's already in a league, it's possible it was an Unranked match.
3. If the game was a Loss, you have to find out whether the player has any Bonus Pool remaining in that game format. If he does, it's possible it was a Ranked game where the lost points were absorbed by the Bonus Pool (this doesn't make it into match history). If he has no Bonus Pool remaining, then either it was a Ranked match that used up the remaining Bonus Pool, or it was an Unranked match.
Q: Can Unranked players play against Ranked players?
A: Yes. Ranked and Unranked players are part of the same pool.
Q: If Unranked players can play against Ranked players, won't they feed rating to the Ranked players since Unranked players generally won't be playing as seriously?
A: This is yet to be determined. Assuming this is true, there would be an initial upward swing for Ranked players as the Unranked players drop in MMR on their way to their Unranked skill level (this can mean many things, from offracing to build practice to casual stress relief). This is just one possibility.
Patch 2.0.4 also introduced a strange new button called "Leave League".
Q: What does this shiny, scary button do?
A: "Leave League" does exactly what it says, ejects you from the ladder. You can rejoin at any time. You play your Placement Match again and are assigned a new league.
Something rather critical about this: some players report having to play one Placement Match (meaning MMR is not reset) and others report having to play five Placement Matches (meaning MMR is reset). I don't have enough information now to determine which is intended.
Q: Can I use Leave League to force a promotion/demotion?
A: League changes (promotions/demotions) require an element of stability. By leaving the league, you sidestep this requirement. However, it's also possible that initial placements are conservative.
Maybe you've noticed that some players have a border around their player portrait now.
Q: How do I get one of those cool portrait borders and what do they mean?
A: The portrait borders reflect your 1v1 league. If you don't have one, it's because you're not in a Ranked 1v1 division. This border persists into team games as well as chat channels.
In the pre-game screen, the "Favored" indicator has disappeared.
Q: How do I know how many points the match is worth for me now that the indicator's gone?
A: Now you can't. Instead, you can only see the opponent's portrait border signifying 1v1 league, but of course that doesn't necessarily tell you about his current MMR. That Gold-bordered opponent could be on his way up to your Platinum division, or maybe he's on a losing streak and hasn't been demoted to Bronze yet. On the plus side, now that bug with the pre-game and score screen Favored indicators not matching up is finally fixed! Note that the way points are determined is still unchanged: your current adjusted points compared to the opponent's MMR, and his adjusted points compared to your MMR. Also, because Unranked players can be matched against Ranked players, he may have a Platinum Unranked MMR but a Master-bordered portrait.