What was one now becomes two

Ever wonder why Classical games could be as fast as 8+0 and as slow as 180+180? So did we! And now we're changing it. We're splitting Classical in two by adding a new, faster, category called Rapid.

What does this mean for me?

Over the next few days we'll be migrating everyone's past games to the right category.

Your ratings will stay the same. For example, if you're rated 1633 in classical right now, you'll be rated 1633 in both rapid and classical after the migration, as long as you've played at least one game at each time control.

Expect some minor issues as we update the opening explorer, the game search index, and so on. 600 million games take a long time to process!

What time controls are which?

If you're playing without an increment, anything shorter than 25+0 is rapid. 25+0 or longer is classical.

With an increment, use this formula:

Starting Time + 40 × Increment

If the result is less than 25 minutes, it's rapid. If it's 25 minutes or more, it's classical.

Why are you making me do math?

Have a look at some common classical time controls and where they fall now:

Rapid

8+0

5+5

20+5

15+10

10+15

Classical

25+0

15+15

20+10

45+45

180+180

Why 25 minutes?

We took in feedback, crunched the data, and in the end 25+0 for classical was the clear choice. When evaluating our rating categories, we wanted to do two things:

Separate time controls that are very different

Ensure all our rating categories are active and thriving

The range for rapid time controls is 8+0 to 25+0, which is comparable in magnitude to the bullet and blitz ranges. Classical is still fairly wide, at 25+0 to 180+180, but we couldn't make it any smaller while keeping it active enough. We hope our 180+180 players forgive us and appreciate the improvement from the previous range of 8+0 to 180+180.

Compared with a slightly higher threshold, 25+0 gives us 3x as many classical games.

Compared with a slightly higher threshold, 25+0 includes 2x as many players in classical.