Matchmaking

Matchmaking (MM) for Random and Co-op Battles

(link)

18 Dec 2020

Battle Tiers

The battle tier (battle level) is the highest tier of the ships in the battle. Each ship has a maximal permitted battle tier of the battles she can be sent to, so this is the highest tier of the ships she may encounter in battle (unless she is in a division with a higher tier ship).

The maximal permitted battle tier is:

• I for Tier I ships
• "Tier + 1" for Tier II-IV ships
• "Tier + 2" for Tier V-IX ships
• XI for Tier X-XI ships

Tier XI is officially called Tier ★.

This leads to the following tables:

Ship Tier	Possible Battle Tiers
	I	II	III	IV	V	VI	VII	VIII	IX	X	★
I
II
III
IV
V
VI
VII
VIII
IX
X
★

Ship Tier	Possible tiers of other ships in battles
	I	II	III	IV	V	VI	VII	VIII	IX	X	★
I
II
III
IV
V
VI
VII
VIII
IX
X
★

Example: A Tier VI ship either gets into a Tier VI battle, a Tier VII battle or a Tier VIII battle. In a Tier VI battle, it can encounter Tier V and Tier VI ships. In a Tier VII battle, it can encounter ships from Tiers V to VII. In a Tier VIII battle, it can encounter ships from Tiers VI to VIII.

Other restrictions

• Both teams have the same number of ships.
• at most 2 aircraft carriers per team (at most 3 in training battles)
• The battle tier determines which map can be used.

Other restrictions in Random Battles

Explanation of "soft limit" / "soft rule": the matchmaker tries to fulfill it but ignores it when players have to wait too long for a battle.

• Mirror Matchmaking: Dev Diaries: Mirror Matchmaking (Update 0.7.4, 2018-04-19)
  • Soft rule: Teams are mirrored by ship types (cruiser etc.) and tiers. This means that for every ship type and tier, both teams have the same number of ships of that type and tier.
• There are soft restrictions on the minimum number of ships allowed that are two tiers lower than the battle tier, and also on the maximum number of ships of the highest tier in the battle.
• If possible, ships of different nations are distributed between teams on an even basis.
• The matchmaker does not try to distribute identical ships evenly.
• soft limit: at most 4 destroyers per team.
• soft limit: at most 5 battleships per team.
• Aircraft Carriers:
  • mirrored. (For every tier, both teams have the same number of carriers.)
  • Battle Tier X: soft limit: at most 1 per team
  • Battle Tiers VIII-IX: soft limit: at most 1 Tier VIII carrier per team.
• Total limit for submarines and destroyers: A total limit has been set for the number of destroyers and submarines in a team. It depends on the waiting time of the first player in the queue:
  • 0–24 seconds: Four ships total; no more than four destroyers and two submarines.
  • 25+ seconds: Five ships total; no more than four destroyers and two submarines.
    In case of longer waiting times for the first player, these limits will be less strict.
• There are upper limits on the percentages of battle tiers a ship will be sent to. For Tier VI–IX ships, the maximum number of battles with ships two tiers higher has been reduced to no more than 37.5% over the last 16 battles. Thus, Tier VI–IX ships will more often find themselves in battles with their own tiers or ships one tier higher.
• "Understaffed" teams (11v11, 10v10, etc.) are possible
• There is a maximum difference of one division between opposing teams within a single battle..
• Top-tier ships are mirrored by type.
• Battleships whose tier is one less than the top tier are mirrored.
• One team has at most 1 battleship more than the other team.
• One team has at most 1 destroyer more than the other team.
• One team has at most 2 cruisers more than the other team.

Low-Tier (I-V) Matchmaking for Random Battles

In Tier I-V battles, if the waiting time spent by the first player in the queue exceeds 3 minutes, the remaining places in the teams will be occupied by bots.

• In Tier I–IV battles, bots are equal in strength to the bots in Co-op Battles.
• In Tier V battles, bots have improved AI and fight at the skill level of those in Operations.

The Matchmaker for Newcomers

A newcomer is a player who has played at most 200 battles. World of Warships has a special queue for newcomers entering Random battle so they gain experience before moving on to general Random Battles. If any newcomers decide they are ready to fight with experienced players, they will be able to do that by playing Tier V+ ships:

• When playing a ship of Tier I–IV, a newcomer is put into the special queue for newcomers only.
• When playing a ship of Tier V or higher, a newcomer is put into the general Random queue.
• Players who have played more than 200 battles will always be placed in the general Random queue.
• If the waiting time spent by the first player in the queue exceeds 3 minutes, battles are possible where there is only one live player mirrored by a bot. In this case, the rest of the player’s team will be filled out with bots, and the opposing team will also be filled with bots, mirroring the player’s team in terms of ship tiers and types.
• A Division can be placed in the queue for newcomers only if all members meet the requirements above (not more than 200 battles, Tier I-IV ship).

Bots in Non-Newcomer Random Battles

• In Tier I–V Random Battles, bots will be added until complete teams are formed if the waiting time spent by the first player in the queue exceeds 3 minutes. A battle will only be matched if the general queue contains at least one pair of players playing ships of the same tier.
• If players have ships of different types, then after 3 minutes of waiting in the queue, they will be mirrored by bot ships of the same types and tiers, and the teams will be complemented with bots within the limits for ship types and tiers for this particular battle tier. It means each team will have the same number of bots.
• A visual notification about the maximum waiting time and possibility of matching bots to the battle is on the battle loading screen.

Other restrictions in Co-op Battles

• The bot team mirrors the player team by type and tier.
• at most 4 battleships and 4 destroyers per team.
• soft limit for battle tiers VI-X: at most 3 battleships and 3 destroyers per team.
• Bots may be added to the player team:
  • cruiser rule: if cruisers are the most numerous type, a destroyer is added.
  • destroyer rule: if destroyers are the most numerous type, a battleship is added.
  • battleship rule: if battleships are the most numerous type, a cruiser is added.
  • if two or more types are the most numerous, the rules are applied in the following order of priority: battleship rule, cruiser rule and destroyer rule.
  • Any bot-driven ship matched into a battle may only be taken from the list of researchable ships, and its tier must equal the lowest tier brought to battle by a player, provided that the required type of ship is available at that tier.
  • If there are no ships of the required type, the next ship type is selected in this order: battleship, cruiser, destroyer.
  • Sometimes an aircraft carrier is added.
  • Bots are added until there are nine players on each team.

Divisions

Divisions of up to three ships can be created. Currently divisions can only have one carrier. Divisions are restricted to a one tier spread. A division with a Tier VI ship, for example, could include ships of Tier V and Tier VI, or Tier VI and Tier VII. Tier V, VI, and VII ships are not allowed in the same division at the same time.

Previously, there were no restrictions on division tiers, leading to "fail divisions" of high tier ships (such as Tier IX or X) divisioned with low tier ships (Tier I or II).

When placing divisions in a match, Match Maker will only consider the highest tier ship's Match Making tier range for purposes of tier placement. For example, a Tier 5's normal Match Making is +2/-1, so it will normally only see Tier 4 through Tier 7 ships in matches. Similarly, a Tier 6's normal Match Making is also +2/-1, so it will normally only see Tier 5 through Tier 8 ships in matches. When divisioned with ships of the same tier, the division will see the normal Match Making for that tier. For example, a division of only Tier 5s will only see matches with Tier 4 to Tier 7 ships. A division of only Tier 6s will only see matches with ships from Tier 5 to Tier 8.

However, when a division is made up of ships of unequal tier, only the top tier ship's tier range will be considered. Thus, let us say the Tier 5 and Tier 6 above form a division. Match Maker will only consider the Tier 6's tier spread. The Tier 6 can see Tier 8 matches, so the Tier 5 in the division with it will now also be subject to seeing Tier 8 matches where it normally would only be able to see Tier 7s max. This results in an effective +3/-1 Match Making spread for the Tier 5 when divisioned with a Tier 6. This is commonly called a "fail division" because this puts the lower tier ship in a battle tier they normally cannot see.

Ship Performance Factors

For each ship there are seven performance factors that provide a basis for comparison of any one ship against another in game. These performance factors are expressed on a relative scale of 0 (worst) to 100 (best). Each performance factor is based on the ship's abilities. Note that these factors are just a basis for comparison, and can change based on what modules, upgrades, or captain skills the ship is equipped with.

• Survivability is a measure of the ship's ability to take damage and keep fighting. Its mainly all about hit points. The T10 BB's IJN Yamato, KMS Großer Kurfürst, HMS Conqueror, USS Montana and MN Republique share top Survivability factor in-game with 100. Many tier one ships share the worst, with 4.*

• Artillery is a measure of the ship's firepower with its main and secondary guns. The main battery firing range in kilometers and the number, type, and positions of the main battery and the secondary armament guns contribute to this factor. The US T10 BB Montana, IJN Yamato and UK T10 BB Conqueror have the top Artillery factor in-game of 94. Asides tier 1 ships, The IJN T2 DD Tachibana has the worst with 2.
• AA Guns is a measure of the ship's anti-aircraft defenses and its ability to defend itself from air attacks. The number and caliber of the on-board AA guns contribute to this factor. The U.S T10 CL Worcester has the best AA Guns factor in-game of 96. Many ships, such as the US premium T4 BB Arkansas Beta, IJN premium T2 DD Tachibana, Russian premium CA Oleg and KM T3 BB Nassau's A hull have the worst - 0 - because they are not armed with any AA Guns.
• Maneuverability factor is a measure of the ship's ability to maneuver, make turns, and maintain speed while turning. Three other factors affect Maneuverability, the ship's "Maximum Speed" in knots, its "Turning Circle Radius" in meters, and its "Rudder Shift Time" in seconds. The IJN T5 DD Minekaze and Russian T5 DD Podvoisky share the best Maneuverability factor in-game - 95. The US T4 CV Langley has the worst at 7.
• Concealment factor is a measure of the ship's ability to remain undetected by the enemy. The Concealment factor is a calculated parameter influenced by the ship's "Surface Detectability Range" and an "Air Detectability Range", each are also specified and expressed in kilometers. The IJN T2 DD Tachibana and it's T10 cousin Shimakaze has the best Concealment factor in-game of 98. The US T10 CV Midway has the worst at 5. Many camouflages, such as the Type-1 Camouflage further reduces the detectability range by sea of the ship it is mounted on by 3%.
• Torpedoes is a measure of the torpedo capability of those ships which carry torpedoes. The number, type, and position of the torpedo tubes and the range of the torpedoes contribute to this factor. The IJN T10 CA Zao has the best Torpedo factor in-game of 64.Its T10 destroyer friend Shimakaze has the second best Torpedo factor of 63. The IJN T2 DDs Umikaze and Tachibana, as well as the USS Smith have the worst rating which is 4. Those ships not armed with torpedoes have no Torpedo factor.
• Aircraft is a measure of the aircraft capability of those ships which carry aircraft. The total number of squadrons, number of planes, and the type and capabilities of each of the planes: fighter, dive-bomber, or torpedo-planes; determine the Aircraft factor. The USA T10 CV Midway has the best in-game Aircraft factor of 86. Cruisers (beginning at T5 except the T4 IJN Kuma), and Battleships of certain tiers, carry 1 to 3 fighter/recon aircraft. Battleships can only mount catapult fighters at tier 7 and up, with the exception of Dunkerque. Only CVs have an Aircraft factor.