[AceWing]

Ladder Changes: You can no longer be demoted during a season!
By GwiyoMI

"To keep play at each skill level on the ladder competitive, we no longer demote players in the middle of a season. You can only be placed into a lower league when you play your initial placement match(es) in a new season, or by leaving the league."

With the global launch of the 2013 World Championship Series and a new season on the StarCraft II ladder approaching, we’ve seen a number of questions about the multiplayer competitive framework that we’d like to answer. What follows are common inquiries that we’ve seen on our forums, Reddit, Team Liquid, and elsewhere.

Question: Why was I initially placed lower on the ladder than my skill/history/placement match results might predict?

Answer: Initial placement each season is conservative. With the launch of Heart of the Swarm, every player was added to an entirely new matchmaking queue and given a new hidden rating based on their initial results. We expected (and saw that) many players got placed into a lower league than they might ultimately reach, and there were many promotions as a result. In subsequent seasons, you won’t be placed as conservatively. As always, as long as you continue to win against opponents on the ladder, you will be promoted.

Question: I’ve been losing quite a bit on the ladder lately. Why am I not being demoted?

Answer: To keep play at each skill level on the ladder competitive, we no longer demote players in the middle of a season. You can only be placed into a lower league when you play your initial placement match(es) in a new season, or by leaving the league.

Question: When I choose to play “unranked”, do I only face other unranked players?

Answer: No. At this time, players who are playing with and without ladder points on the line are in the same pool. In order to expand the interests of players who choose to play unranked, the game maintains a separate hidden skill rating for ranked and unranked play.

At the highest levels of skill, ranked players are only matched up against other ranked players, and unranked players are only matched up against other unranked players.

Question: What happens if I choose the “Leave League” option?

Answer: Simply put, it removes you from the ladder. You will no longer belong to any league, as though you never played your placement matches, and your bonus pool will be reset.

This does not affect your hidden skill rating. You can play a placement match and be inserted back into the ladder at any time.

Question: How do the Wings of Liberty and Heart of the Swarm ladders differ?

Answer: The two different expansion levels each have their own ladders, and you must switch down to Wings of Liberty (or upgrade to Heart of the Swarm) in order to queue for that ladder. In terms of placement, ranking, promotion, matchmaking, and functionality, the two ladders work exactly the same.

If you play on both ladders, you have two hidden skill ratings – one for each ladder.

Question: How long is a ladder season?

Answer: The 2013 ladder seasons have been aligned with the World Championship Series. The start dates for each season are:

2013 Season 3 – June 10
2013 Season 4 – August 26
2013 Season 5 – November 11

Currently, each season is 11 weeks long.

This compilation of frequently asked questions (and answers) will be updated as necessary, so please feel free to continue the discussion in the comments below.

Source: http://www.blizzposts.com/blogentry/...and-season-faq