League of Legends: How is Win Probability calculated in pro play

Using key in-game metrics, such as real-time gold differences and the team's respective side, Win Probability (WP) determines the likelihood of a League of Legends team winning based on similar historical situations. This machine-learning-based tool provides a percentage representation to show the team's chances of victory.

Using an ML algorithm called xgboost, the WP takes into account various factors and is developed by analyzing the number of teams that have faced a similar scenario and won the game.

This article will guide you through how the calculation works for the Win Probability in League of Legends Worlds 2023.

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How does the Win Probability in League of Legends work?

Win Probability in LoL Worlds 2023 (Image via LoL Esports/X)

The WP model, which Riot Games shed light on, factors in a few things. It has been utilized on all professional League of Legends esports matches since patch 10.4 and gets updated regularly with new game results. This allows it to factor in changes to the game and the meta over time.

The following facets are taken into consideration by the WP model:

• Game time (the in-game time)
• Gold % (player gold/total gold in-game)
• Total team XP
• Number of players alive
• Tower kills
• Dragon kills (whether a team has a dragon soul or not)
• Herald trinket in Inventory
• Inhibitor timers (how long until an inhibitor respawns) for each inhibitor
• Baron timers (time until Baron buff expires for the team)
• Elder timer (time until Elder Dragon buff expires for the team)
• Number of players with Baron active
• Number of players with Elder active

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Win Probability at League of Legends Worlds 2023

The Mid-Season Invitational 2023 saw Riot Games team up with their partners to bring forth the initial machine learning model, output APIs, broadcast graphics, and more, all of which contributed to Win Probability. As we gear up for Worlds 2023, Riot intends to build on this and polish the final product, which includes:

• Refreshing the WP graphic to be more visually distinct
• Increasing transparency about the underlying technology
• Improving education for our fans, casters, and community

When assessing League of Legends, there are numerous elements to take into account, such as the effectiveness of team compositions, the strategic placement of champions, the selection of items and runes, and so forth. This can be quite overwhelming, but Riot strives to continually develop the WP framework to accurately reflect the present state of the game.