Matchmaking



Matchmaking is the process through which the system groups players into opposing teams for public games. With the exception of bot games, matchmaking is mostly determined by matchmaking ratings (MMR).

Criteria
Valve has stated that matchmaking tries to fulfil several criteria within a reasonable amount of time:


 * The teams are balanced. (Each team has a 50% chance to win.)
 * The discrepancy in skill between the most and least skilled player in the match is minimized.
 * The highest skill Radiant player should be close to the same skill as the highest skill Dire player.
 * The discrepancy between experience (measured by the number of games played) between the least experienced player and the most experienced player is minimized.
 * Each team contains about the same number of parties.
 * For example, the matchmaker tries to avoid matching a party of 5 against against 5 individual players.
 * Players' language preferences contains a common language.
 * Wait times shouldn't be too long.

Unranked Games
Unranked or casual games do not display matchmaking ratings. Two MMRs are still tracked for solo and party queues, but kept hidden from players.


 * All PvP game modes are available for unranked matches.

Ranked Games
Ranked matches track and display two visible matchmaking ratings, one for solo queue, and one for parties.


 * Only All Pick, Captains Draft, and Captains Mode are available for ranked matches.
 * Players must play 10 trial games for the system to calibrate their MMR.
 * Players must be have finished approximately 150 games.
 * Players must be above Profile Level 13 to queue for ranked matches.
 * Parties with any player below the Profile Level requirement will not be able to queue for ranked matches.
 * Players in Low Priority cannot queue for ranked matches.
 * Parties with any player in Low Priority will not be able to queue for ranked matches.
 * Parties of 4 are unable to queue for ranked matches.
 * Coaches are not permitted in ranked matches.
 * Parties with members whose MMRs are too far apart (numbers needed) are unable to queue for ranked matches.
 * Any form of Abandonment will incur full penalties for the entire team.
 * Any player who abandons will automatically receive a loss, regardless of the match's outcome.
 * Separate MMRs are maintained for both solo and party queueing.
 * Unlike casual matches, MMRs for all players in ranked matches are made visible at the endgame screen.
 * A player's ranked MMRs can also be viewed by friends and party members on their profile screen.

Team games
Matches your team against another random team. You must be in a team to queue for this function.


 * Team matches are always played in Captains Mode.

Bot Games
This function matches you or your team against AI-controlled bots.


 * Co-op bot matches are always played in All Pick mode.
 * No MMR is tracked for bot matches.

Settings
Settings allow players to be matched only with others who have selected the same settings. Selecting more settings can significantly reduce wait time, as the system will be able to search for compatible players from a larger population pool.

Game Modes
Game Modes determines which modes you would like to queue for. Checking more game modes will increase matchmaking speed.

Current game modes for public matchmaking include:


 * All Pick
 * Single Draft
 * Captains Mode
 * Random Draft
 * Least Played
 * All Random
 * Limited Heroes
 * Captains Draft
 * Ability Draft

Region
Region determines which regional server you would like to play on. Checking more regions will increase matchmaking speed, but may cause latency issues if the server location is far away. You can select up to 3 regions.

Current regions include:


 * US West
 * US East
 * Europe West
 * Europe East
 * Russia
 * South America
 * SE Asia
 * Australia
 * Dubai
 * South Africa

Preferences
The preference window allows you to select up to 3 languages. You will be matched with other players who have selected the same languages. Checking more languages will increase matchmaking speed. If no languages are checked, you will be matched with people of any language preference (fastest matchmaking speed).

Matchmaking Rating
All PvP matchmaking is based on an Matchmaking Rating (MMR) similar to the Elo system. Players of roughly equal skill will be placed in the same game.

Penalties

 * Players who decline or fail to accept a ready match are blocked from finding another match for a small amount of time.
 * Players who decline or fail to accept a ready match repeatedly may be placed in Low Priority.

Priority
Priority determines how quickly the player is matched with other players. There are 3 types of priority: high priority, base priority, and low priority. Players in low priority will not gain battle points from the match, will find games slower and will be put with other players in low priority. Low priority is a common punishment for abandonment.