Changes Coming to League of Legends Competitive Format - GameSpot

The North American league will shift from a best-of-one to a best-of-three while the European league will shift to a best-of-two.
League of Legends is a multiplayer online battle arena game (MOBA). Players choose a role from an expanding cast of powerful champions and join forces in strategic, fast-paced gameplay to take control of the enemy’s end of the battlefield.

Dreamhack Summer announce $30,000 League of Legends tournament - GameSpot

League Championship Series (esports) - Wikipedia

Worlds 2024 format currently being reviewed say Riot Games

8 Out of 10 NA LCS Players Want Format Change to Best of Two - GameSpot

Impact - Leaguepedia League of Legends Esports Wiki

NA LCS 2015 Summer - Leaguepedia

[LTR] - Generous Ent - (GameSpot) : r/magicTCG

Friction between Riot and League of Legends team owners

Riot reveals massive MSI and Worlds format changes for League in 2023