Rating System in Connect Four

The rating system on play4row uses Glicko-2, a modern improvement over the classic Elo system. Every new player starts with a rating of 1500. Win games and your rating goes up. Lose games and it goes down. The amount it changes depends on your opponent's rating and a special value called "rating deviation" that measures how certain the system is about your true skill level.

Rating deviation (RD) is what sets Glicko-2 apart from basic Elo. When you first start playing, your RD is high because the system does not know how strong you are. High RD means your rating changes by large amounts after each game. As you play more games, your RD decreases. The system becomes more confident in your rating, so it adjusts by smaller amounts. If you stop playing for a while, your RD gradually increases again, reflecting the uncertainty about whether your skill level has changed during the break.

Glicko-2 also includes a "volatility" parameter that tracks how consistently you perform. A player who wins and loses unpredictably has high volatility. A player who performs steadily has low volatility. The system uses this to fine-tune how much your rating changes. Consistent players see smaller adjustments. Erratic players see larger swings. This prevents a single lucky win or unlucky loss from distorting your rating too much over time.

Here is how the math works in practice. Beating a player rated much higher than you gives a big rating boost. Losing to someone rated much lower costs you more points than losing to an equal. Draws (which do not happen in standard Connect Four, but the system supports them) adjust your rating toward your opponent's level. The system converges on your true skill over roughly 15 to 20 games. After that, your rating is a reliable indicator of your playing strength. Compare your rating to the leaderboard to see where you stand in the community.