Draw Rate
Overall draw rate
Out of 135679 KCEC games played so far 33018 ended as a draw.
This makes the overall draw rate of 24.3%.
Draw rate vs rating difference
Naturally the chance to get a draw is higher when both engines are of similar strength:
Each point represents a match of two engines.
Linear regression (blue line in the graph above):
Draw rate = − R.Diff / 22.37 [±2.25] + 27.95 [±0.46]
Draw rate vs average rating
As expected, strong engines make more draws:
Each point represents a match of two engines.
Linear regression (light blue straight line in the graph above):
Draw rate = Av.Rating / 87.96 [±7.67] − 2.13 [±2.32]
Exponential curve (purple curve in the graph above):
Draw rate = exp((Av.Rating − 2054.0 [±118.2]) / 271.93 [±43.73]) + 20.00 [±0.72]
Draw rate vs rating difference and average rating
If you try to use both Rating difference and Average rating, you may end up with something like this:
Draw rate = − R.Diff / 32.49 [±4.85] + exp((Av.Rating − 2254.7 [±85.7]) / 208.49 [±34.04]) + 23.87 [±0.76]