Your rating starts the night before

There’s something almost impressive about the confidence chess players have in their brains after sleeping four hours. Someone will go to bed at 3 am after blitzing angry rematches, wake up feeling half alive, drink a coffee strong enough to restart a small village, and still expect to calculate a complicated middlegame like everything is fine.
Then the games start, and suddenly every position feels annoying. Not losing, not terrible, just mentally heavy. You look at a position you normally understand, and your brain decides that calculating one more variation is simply too much work today. You stop one move earlier than usual, you play faster just to escape the tension, a small mistake feels personal, and one loss somehow turns into five because now it’s no longer chess - it’s emotional damage control.

Most players don't notice the drop. They just feel more impatient, more reactive, and more annoyed by positions they'd normally handle. And there's actual research behind this:
A 2020 study followed 14 Norwegian chess players over 120 days. Seven of them saw their FIDE rating decline, the other seven improved. When researchers compared their sleep patterns, the difference was clear. The group that progressed had more deep sleep, less REM sleep, and a lower nighttime breathing rate than those whose rating stagnated or dropped. Not more training, not more openings. Deeper sleep.
Another study of 225 tournament players found that those who slept better didn’t just feel sharper - they showed measurable improvements in focus and decision-making speed.
Even Magnus Carlsen reportedly aims for 9 to 10 hours of sleep before important tournaments. Meanwhile online players treat sleep deprivation like some kind of training method..

After enough bad sleep, poor performance starts to feel normal. Your brain adapts to working below its real level, so you stop noticing how much clarity you've lost. You just feel stuck and blame your chess, when sometimes your nervous system is simply exhausted.


What can you actually do? Here are a few small things that can help:

• If every position suddenly feels irritating, your brain probably needs recovery more than another rematch, take a nap and go to bed earlier that day. Your Elo will thank you later.
• Late-night rated sessions are usually a terrible deal between your elo and your nervous system, especially after a stressful day. If you're tired, don't queue. Play unrated, do puzzles, or just sleep.
• Sleeping properly for a week will likely improve your chess more than obsessively watching another opening course at 1 am.

Chess players spend years trying to optimise calculation, openings and strategy while completely ignoring the organ that’s actually doing all the work. Because chess is not only about how much you study. Sometimes your rating starts the night before. 

Enjoy playing!
More articles here
Follow me on Twitch