Global Smash Power
Global Smash Power, (世界戦闘力, World Combat Power) abbreviated GSP, is the online ranking system found in Super Smash Bros. 4 and Super Smash Bros. Ultimate. Announced during the Super Smash Bros. Direct, GSP is a version of an Elo rating system that ranks all players' scores on a numeric scale, with the number being related to how many players that player outranks. For example, a player with a rank of 251,357 would have a better score than 251,356 other players. The system is unusual for being an inverse ranking system; whereas other games would feature 1 as the best player, Global Smash Power would rank 1 as the worst player (meaning that the player is better than 0 other players). This system was developed with the intention of a more friendly scale to players of lower skill, using "your score is better than X players" instead of "your score is worse than X players" as a metric.
There are pros and cons to this system compared to others. The major advantage is that it taps into the idea of "numbers go up" being inherently satisfying to humans. Low GSP players have a clear, easy to understand goal of climbing the ranks and receiving a larger number, and high GSP players have the satisfaction of knowing exactly how many players the game considers them better than. The major disadvantage is that players cannot measure how far they are from the top-ranked player, and that the top-ranked player cannot even know that they are the top-ranked player without hard data on player count. When players realize there is no endgame in sight, they might experience goal fatigue and simply stop trying to be competitive.
In Smash 4, Global Smash Power is used only for solo play modes (and separately for their co-op equivalents), and not for multiplayer matches. However, according to Masahiro Sakurai, there is "some sort of matchmaking" during online play, though this matchmaking system is not visible to players.
The following modes feature Global Smash Power rankings:
In each of these modes, Global Smash Power is displayed for each individual high score as well as for the player's total high score (i.e. the sum of their high scores with each character). Global Smash Power is also shown during gameplay and rises along with the player's score, allowing them to see how many other players they have already outranked before finishing.
Global Smash Power rankings are updated whenever the player goes online. If they have not yet been online at all, Global Smash Power is not displayed.
In Ultimate, Global Smash Power is also used to determine whether a player's character is allowed to participate in Elite Smash. The value of Global Smash Power is not set, and rises as more people meet the threshold.