This page briefly describes the ranking system used by PlanetsCentral.

Your rank is determined by three values:

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
 
Commander9000
 
85 250
12
 
Captain12000
 
85 300
13
 
Rear Admiral16000
 
95 300
14
 
Vice Admiral25000
 
95 400
15
 
Admiral50000
 
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:1st2nd3rd4th5th6th7th8th9th 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.