Draw Rate in Chess Tournaments

We have run an analysis over 8 million chess tournament games and estimated the draw rate (percentage of draws compared to total games played) depending on: the average rating of opponents (aR =(Elo1+Elo2) / 2) and the rating difference between the opponents (rt = abs[Elo1-Elo2]) For example, if you have two playes one having Elo rating 2200 and the other one 2310:
a) The average rating is 2255 (Rounded to the lower multiple of 200, thus in the chart below you need to take the graph for "2200")
b) The rating difference is 110 (Rounded to the lower mutliple of 20, thus in the chart below the X-axis value to select is 100)
So, for average rating 2200 and rating difference of 100 we have draws in 36% of the games.

See also

1. Kirill Kryukov's draw rate estimations.
2. Chess programming Wiki match statistics.