Specifies the type of calculations used to determine how a player skill changes from a kill. A description of each calculation available is detailed below.

The '<b>default</b>' calculation is a new method that uses the relative skill values of the players but is more stable over time compared to the old 'elo' method and the players online time is not taken into account. A 'base skill' around 50 is recommended when using this formula.

The '<b>elo</b>' calculations use the ELO formula (which is often used in chess games). ELO tries to rate players based on their relative skill values to each other. Player's online time is also a factor and the longer a player plays the more stable their skill becomes (this is not part of the original ELO formula). It is argued that this formula is not actually that stable or accurate for a first person shooter type of game. A 'base skill' around 10000 is recommended when using this formula. Up to PsychoStats v3.0 this was the original and only calculation available. This is no longer the default calculation used in versions 3.1 or newer.

<b>Recommendation:</b> default