PlanetsCentral

Version 20241025

This page briefly describes the ranking system used by PlanetsCentral.

Your rank is determined by three values:

your skill. You receive skill points for every game you finish.
your reliability. Only reliable players can reach high ranks.
your experience. You need to play a specific number of turns to reach a rank.

These values determine your rank:

			. . . . Minimum . . . .
Nr.	Rank		Skill	Reliability		Turns
1		Spaceman Recruit	0		0	0
2		Spaceman Apprentice	100		55	20
3		Spaceman	250		55	40
4		Petty Officer	500		65	60
5		Chief Petty Officer	800		65	80
6		Senior Chief Petty Officer	1200		65	100
7		Ensign	1750		75	100
8		Lieutenant Junior Grade	2500		75	150
9		Lieutenant	4000		75	200
10		Lieutenant Commander	6500		85	200
11		Commander	9000		85	250
12		Captain	12000		85	300
13		Rear Admiral	16000		95	300
14		Vice Admiral	25000		95	400
15		Admiral	50000		95	500

Skill

You gain skill points for every game you finish. The amount you get depends on your position, the game difficulty, the ranks of your opponents (a Spaceman winning against an Admiral gets more points than the other way around), your reliability for this very game, and the length of the game (games shorter than 50 turns get you fewer points).

New_skill_points =
    100 * Position_points
        * Game_difficulty
        * Rank_difficulty
        * Reliabity_rate
        * Turn_factor

Position_points =
    Table_value * (Num_players / 11)

Position:	1st	2nd	3rd	4th	5th	6th	7th	8th	9th and later
Points:	20	14	10	8	6	4	3	2	1

Game_difficulty =
    (1.0 for normal game, >1 for harder games; see here)

Rank_difficulty =
    (Sum(Ranks_of_beaten_opponents) + 110)/(Own_rank * No_of_opponents + 110)

Reliability_rate =
    (Submitted_turns / Total_turns)^2

Turn_factor =
    min(Total_turns / 50, 1)

Reliability

Reliability is expressed as a number between 0 and 100. This value expresses your current reliability. If you submit turns, your reliability will approach 100. If you miss turns, your reliability will drop. If you drop from a game, your reliability will drop, depending on your position in the game (i.e. if you leave an almost-dead empire, there will be just a slight penalty; if you leave an active game in the middle, the penalty will be bigger).

Formulas for turn submission:

New_reliability =
    Old_reliability * (100 - Speed) / 100 + New_points * Speed

New_points =
    1.0      if turn submitted
    0.0      if turn missed
    0.5      if your replacement missed the turn
    0.75     if your replacement's replacement missed the turn

Speed =
    3.0      (configuration option)

Formula for dropping from a game:

New_reliability =
    Old_reliability * (1 - Your_score / Score_of_best_player_in_game)

Note that the Reliability is not an absolute turn submission rate. It will track your current turn submission rate. If you used to be a very reliable player, but start missing turns, it will drop. Likewise, if you used to be a lousy player but start getting serious, it will rise. It will slowly "forget" yesterday's sins (at the speed set by the Speed configuration option).

Also note that if your reliability drops too far below the requirement for your current rank, you will be demoted.

Colophon

This ranking system is heavily based upon the PlanetsServer ranking system. Actually, the rank names and levels are the same. The reliability is computed differently, though.

The game difficulty formula uses the Vagabond's VPI computation as the Production rating.