Whether in an online game, a sports league or chess, the win rate is the simplest measure of performance. Raising it gets harder the more games you have already played. This calculator shows exactly how much work a target takes.
Win rate
win rate = (wins + ½ × draws) ÷ games played
With 45 wins and 55 losses, the win rate is 45%. Counting a draw as half a win is the convention in chess and many other games; some games ignore draws.
The winning streak needed
How many wins in a row would bring you to the target? If w is the current wins, n the games played and t the target:
wins in a row = (t × n − w) ÷ (1 − t)
To go from 45% to 55% after 100 games: (55 − 45) ÷ 0.45 = 22.2, so 23 straight wins.
At a realistic rate
Streaks are rare. If from now on you expect to win a share f of your games, higher than the target:
games needed = (t × n − w) ÷ (f − t)
At 60%: (55 − 45) ÷ 0.05 = 200 games. The closer your future rate is to the target, the more games it takes; if your rate is at or below the target, you will never reach it.
Why it gets harder over time
Each new game counts for less as the total grows. After 100 games, one win moves the rate by about half a point; after 1,000 games, by a twentieth of a point. That is why long-time players’ win rates barely move and why a hot streak early on looks dramatic.
Win rate versus rating
Many competitive games use a rating system such as Elo or Glicko instead of the raw win rate, because matchmaking pairs players of similar skill, which tends to push everyone’s win rate toward 50%. A 50% win rate in ranked play is normal and means you are matched well. Look at your rating trend to measure improvement, and use win rate to compare characters, decks, openings or strategies.
A note on small samples
A win rate over 20 games says little: random variation can easily swing it by 10 points or more. Wait for at least 100 games before drawing conclusions about a deck or a strategy.