There are several handicap options for leagues:
No Handicap - Just like the name says, there's no handicap. Both teams start the game even.
Spot Darts - The score of the match starts even for both teams. The lower rated players are given a specified number of "free" darts to throw at the start of each game. This is automatically determined based on the averages of the players involved.
Spot Points & Marks - Lower rated players are given a head start in x01 games (spot points), and automatically given "free" marks in cricket games. This is based on the averages of the players involved.
e.g: in a 501 game, the higher rated team starts at 501 and the lower rated team starts with a score between 501-301.
Reverse Handicap - This is an option that applies to x01 games only. The higher rated players have extra points added to their score at the start of the game.
e.g.: The lower rated team starts at 501 and the other team starts with a score between 501 & 701, depending on the averages of the players involved.