Nikola is an online chess engine that adapts to your skills to offer the most stimulating games possible.
Difficulty will be relatively low initially and change to match your current ability. Once it stabilizes, you should only be able to beat it a fixed fraction of the time, which will remain more or less constant even as you get better.
This fractions ranges between 20% and 75% and is assigned once for each player. Once more data becomes available, we will narrow the range for optimal results.