What is Wratings?

Wratings is an effort to provide an evidence-based seeding tool and performance metric for esports. Our first focus is Super Smash Bros. Ultimate, with additional games to follow.

At its core, a Wrating estimates the probability that a player will win a match against a given opponent, based entirely on observed tournament data. Wratings utilizes modern Bayesian inference and graph theory to calculate the mathematical probability of match outcomes, rather than relying on subjective panels or win/loss ratios.

The Engine: OpenSkill & Bayesian Inference

At the core of Wratings is OpenSkill, an open-source implementation of the Plackett-Luce model (conceptually similar to Microsoft's TrueSkill ). Traditional ranking systems assign a single number to a player. OpenSkill, however, tracks two distinct variables for every competitor:

μ (Mu): The system's estimation of the player's actual skill.
σ (Sigma): The system's level of uncertainty regarding that skill.

When a new player enters the system, their uncertainty (σ) is extremely high. As they play more matches, the system gathers evidence, and σ decreases.

Because Wratings is designed as a professional seeding tool, it must be conservative. We calculate the final leaderboard wrating using the formula μ - 3σ. This represents a 99.7% confidence interval. The system assumes a player is at the absolute lower bound of their estimated skill until they consistently prove otherwise through volume and performance.

Graph Theory: Ponds, Bridges, and Tiers

Wratings separates players into Tiers, rather than forcing all players into a single, unified list. This is to prevent mathematically invalid lists.

Imagine two isolated local tournament scenes—two separate ponds. If no player from Pond A has ever competed against a player from Pond B, there is zero mathematical evidence to compare them. Any system that ranks a player from Pond A above or below a player from Pond B is guessing.

Wratings solves this using graph theory. We map every match as a connection between players. A Tier in Wratings is a "disjoint connected component"—a mathematically isolated group of players.

For two Tiers to merge, players must travel between them. If a competitor from Pond A travels to a major tournament and plays someone from Pond B, they create a Bridge. The OpenSkill algorithm uses that bridge to calibrate the relative strength of both ponds, allowing them to be accurately ranked on the same list. If you are in Tier 2, it simply means you share no common opponents with the players in Tier 1.

Dynamic Systems: Why Wrating Values Shift

Sudden shifts in the leaderboards—sometimes occurring overnight, even when a player hasn't entered a tournament—is common and expected. This is the intended behavior of a dynamic Bayesian system, driven by two main factors:

1. The Sliding Time Window

Competitive form is not static. Wratings calculates performance across specific timeframes (e.g., a 100-Day Season). As time moves forward, the window slides. If a player won a major tournament exactly 101 days ago, that data point falls out of the current window today. The sudden loss of that positive evidence will cause their rating to adjust downward, reflecting only their recent activity.

2. The Ripple Effect

In a connected graph, every match affects the entire network. Suppose you defeat Player X at a local tournament. A month later, Player X travels to a major and defeats the world champion. The OpenSkill engine retroactively realizes that Player X is much stronger than initially estimated. Because Player X's μ increases, your past victory over them becomes mathematically more impressive. Your rating will increase today, based on a match someone else played yesterday.

A Living Record of Competition

Because of these mechanics, Wratings is not a static leaderboard—it is a living ecosystem. Every set played at a local weekly, a regional qualifier, or an international super-major adds a new thread to the web, refining the probabilities for everyone connected to it.

By embracing the math behind the matches, Wratings offers the community a transparent, unbiased, and continuously evolving portrait of esports.