user24585: I've been playing chess from many years but started playing more from past few month. I only play 3 minute blitz games, have rating around 1350 in chess.com and 1700 in lichess, have played few thousand games till now.
I observed that sometimes my brain just doesn't seem to work and am unable to find even the simple moves fast. I won't be able to think few moves ahead. I keep losing games continuously till my rating goes down by 100s of points. This happens for days together. And sometimes, it magically happens that my brain works quick, analyses and find the best moves naturally without any strain.
Does anyone feel the same when playing blitz games? How do you bring yourself into 'that sweet spot' where the brain is active and quick?

user13012: You might consider the possibility of a real illness. What you describe is a symptom of hypothyroidism, which means that you have an inactive thyroid gland. Another symptom of this condition is feeling cold and shivery. I speak from experience. It can be treated with thyroxine tablets.

user23631: 1700 on Lichess is good, but not amazing - it puts you in the top 45% of people who play blitz on Lichess.  It's the sort of platform from which you can decide to dedicate time, effort, and hardship, to excel and maybe aim for a title one day, but it's also still very reasonable to chill out there and just enjoy yourself.
If you're not looking to reach for those heights yet, or at all, don't focus on the rating points.  Play blitz until you're not having fun, or you need to go do the washing up/go to work.  If you are winning and having fun, the points you're gaining aren't what matters.  If you're losing and having fun, the points you're losing are irrelevant.
With that out of the way, I have personally found that it's mostly familiarity and sleep.  For a period, I completely shirked bunch of responsibilities (don't do that) and played the heck outta bullet, used the "analyse your mistakes" feature on lichess, looked up openings, and slept whenever I felt tired, with no alarm to wake me up.  During this time, not only did I have a great deal of fun, my rating went up quite a bit, and I think I improved (as my rating stayed there).
Now I've been playing mostly atomic for several months, and not spending nearly as much time playing standard chess, and sleeping in such a way to line up with a full time job which very much destroys me.  My standard play feels very much like you describe your "brain fog".
So long as you've having fun, just stick to it, and make sure you're sleeping right.  It's also worth making sure you're eating right, too, but I have no experience with poor diet's effect on my psychology 'cause I always eat reasonably well.

user13674: Fatigue is likely a factor. It's common in older players like myself and with playing a lot in a short time. I'm worst in the afternoon games 3 & 4 of a one-day tournament.
But it also may be akin to stage fright. I play best against familiar players in our club or online with friends. I miss many good shots in a tournament, against strangers or with players I'm supposed to beat ( because they're lower rated ).
Your opponent may also be affected. Years ago I drew a game against our States previous Senior Champion. He was about 500 ELO better than me. I was relaxed with little expectation of winning. He seemed intense, made an impulsive move, and I won.

user24511: I think what you are experiencing is fairly common. I find that I have games that i feel like an absolute legend, able to come up with creative solutions and just not making any mistakes.... then there other games where i hang pieces , miscalculate large trades and just can't get things to click.
I think its partially due to fatigue though. If you are playing game after game after game, especially with blitz , theres little time to think and your brain starts to fatigue and you start making mistakes.
I think the best way to do deal with this just recognizing when you are starting to get fatigued and take a break. I find puzzles are really good for helping me with this. I usually do puzzles for half an hour, take my time try to calculate things out a little. then have a cup of tea, then good to go.

24585: <p>I've been playing chess from many years but started playing more from past few month. I only play 3 minute blitz games, have rating around 1350 in chess.com and 1700 in lichess, have played few thousand games till now.</p>
<p>I observed that sometimes my brain just doesn't seem to work and am unable to find even the simple moves fast. I won't be able to think few moves ahead. I keep losing games continuously till my rating goes down by 100s of points. This happens for days together. And sometimes, it magically happens that my brain works quick, analyses and find the best moves naturally without any strain.</p>
<p>Does anyone feel the same when playing blitz games? How do you bring yourself into 'that sweet spot' where the brain is active and quick?</p>
 13012: <p>You might consider the possibility of a real illness. What you describe is a symptom of hypothyroidism, which means that you have an inactive thyroid gland. Another symptom of this condition is feeling cold and shivery. I speak from experience. It can be treated with thyroxine tablets.</p>
 23631: <p>1700 on Lichess is good, but not amazing - it puts you in the top 45% of people who play blitz on Lichess.  It's the sort of platform from which you can decide to dedicate time, effort, and hardship, to excel and maybe aim for a title one day, but it's also still very reasonable to chill out there and just enjoy yourself.</p>
<p>If you're not looking to reach for those heights yet, or at all, don't focus on the rating points.  Play blitz until you're not having fun, or you need to go do the washing up/go to work.  If you are winning and having fun, the points you're gaining aren't what matters.  If you're losing and having fun, the points you're losing are irrelevant.</p>
<p>With that out of the way, I have personally found that it's mostly familiarity and sleep.  For a period, I completely shirked bunch of responsibilities (don't do that) and played the heck outta bullet, used the &quot;analyse your mistakes&quot; feature on lichess, looked up openings, and slept whenever I felt tired, with no alarm to wake me up.  During this time, not only did I have a great deal of fun, my rating went up quite a bit, and I think I improved (as my rating stayed there).</p>
<p>Now I've been playing mostly atomic for several months, and not spending nearly as much time playing standard chess, and sleeping in such a way to line up with a full time job which very much destroys me.  My standard play feels very much like you describe your &quot;brain fog&quot;.</p>
<p>So long as you've having fun, just stick to it, and make sure you're sleeping right.  It's also worth making sure you're eating right, too, but I have no experience with poor diet's effect on my psychology 'cause I always eat reasonably well.</p>
 13674: <p>Fatigue is likely a factor. It's common in older players like myself and with playing a lot in a short time. I'm worst in the afternoon games 3 &amp; 4 of a one-day tournament.</p>
<p>But it also may be akin to <em>stage fright</em>. I play best against familiar players in our club or online with friends. I miss many good shots in a tournament, against strangers or with players I'm supposed to beat ( because they're lower rated ).
Your opponent may also be affected. Years ago I drew a game against our States previous Senior Champion. He was about 500 ELO better than me. I was relaxed with little expectation of winning. He seemed intense, made an impulsive move, and I won.</p>
 24511: <p>I think what you are experiencing is fairly common. I find that I have games that i feel like an absolute legend, able to come up with creative solutions and just not making any mistakes.... then there other games where i hang pieces , miscalculate large trades and just can't get things to click.</p>
<p>I think its partially due to fatigue though. If you are playing game after game after game, especially with blitz , theres little time to think and your brain starts to fatigue and you start making mistakes.</p>
<p>I think the best way to do deal with this just recognizing when you are starting to get fatigued and take a break. I find puzzles are really good for helping me with this. I usually do puzzles for half an hour, take my time try to calculate things out a little. then have a cup of tea, then good to go.</p>
