@ihs7/ts-elo v0.3.0

@ihs7/ts-elo

ELO calculation library in TypeScript

Supports heads up, team and multiplayer calculations

Installing ts-elo

npm i @ihs7/ts-elo

Two player scenario

Create and calculate match between two players

• Player 1 has 1200 rating and wins
• Player 2 has 1320 rating and loses
• Get results

const match = new Duel();
match.addPlayer(new Player("player-identifier-1", 1200), true);
match.addPlayer(new Player("player-identifier-2", 1320), false);
const results = match.calculate();

Three player scenario

Create a match between three players

• Player 1 has 1280 rating and places 1st
• Player 2 has 1300 rating and places 2nd
• Player 3 has 1220 rating and places 3rd
• Get results

const match = new FreeForAll();
match.addPlayer(new Player("player-identifier-1", 1280), 3);
match.addPlayer(new Player("player-identifier-2", 1300), 2);
match.addPlayer(new Player("player-identifier-3", 1220), 1);
const results = match.calculate();

The calculations is based on:

• Player 1 won Player 2 and Player 3
• Player 2 won Player 3 and lost to Player 1
• Player 3 lost to Player 1 and Player 2

Two versus two scenario

• Team 1 consists of Player 1 with 1230 ELO and Player 2 with 1260 ELO
• Team 2 consists of Player 3 with 1120 ELO and Player 4 with 1410 ELO
• Team 1 wins Team 2
• Get results

const match = new TeamMatch();
const team1 = match.addTeam("1", 2);
team1.addPlayer(new Player("player-identifier-1", 1230));
team1.addPlayer(new Player("player-identifier-2", 1260));
const team2 = match.addTeam("2", 1);
team2.addPlayer(new Player("player-identifier-3", 1120));
team2.addPlayer(new Player("player-identifier-4", 1410));
const results = match.calculate();

Each team has a rating which is an average of the team members.

Team 1 has a rating of 1245 ((1230+1260)/2)

Team 2 has a rating of 1265 ((1120+1410)/2)

Get expected score between two ratings

Say you have two players, one with 1460 ELO and another with 1130 ELO, and want to know the likelihood of one winning another.

const player1 = new Player("player-identifier-1", 1460);
const player2 = new Player("player-identifier-2", 1130);
const expectedScore = player1.expectedScoreAgainst(player2);

This returns a float number and in this specific scenario the value is 0.8698499 meaning the higher ranked player is estimated to win 87% of encounters.