Best Speed for improvement

What do people think is the best speed/time controls to play at for improvement?

Bullet/blitz/rapid/classical?

Should you play all of them?

Concentrate on just one?

You've joined chess.com in 2008 and already have a rating of 1800 in rapid. I feel like you already know what is best for improvement, but I'll answer anyway; just in case you don't know, or for others reading this.

Generally speaking, longer time controls are better for improvement. It gives you more time to think and hopefully play better quality moves (but with more time, your opponent will also play better quality moves as well). The time is needed to calculate deeper, consider other candidate moves, blunder-check before you move and so on.

Speed chess (bullet/blitz) does have some merits to it and it can be used for improvement when utilized correctly, but most people don't utilize speed chess correctly and they just play a ton of games for fun without analyzing them.

The biggest danger of speed chess is that it conditions your mind to move quickly and this can be a huge weakness in longer time control games if you aren't able to switch mindsets and slow down for those time controls.

What time control is best for you depends on your current level of understanding (speed chess more acceptable for players already higher rated and with more overall experience) as well as your goals for chess (if your goal is to have fun and speed chess is fun for you, then just go for it! If your goals are long-term improvement, then you probably shouldn't solely play speed chess).

https://www.chess.com/article/view/is-speed-chess-good-for-you

Oh, I forgot to answer this part as well.

I recommend having one time control (preferably rapid or classical) which is your "main" time control and then perhaps having at least one other time control which you play occasionally (like bullet or blitz) but don't care about as much; still care some, but not as much as the main time control you play.

The reason I recommend this is because I think our identity and ego can sometimes get "too attached" to the rating numbers (even if we try not to) and having a time control you care less about can be a good way to play rated chess when you don't feel like risking your "main rating" but still want to play rated chess.

I also recommend at least 2 time controls because you don't want to condition your brain into ONLY one time control pace; having 2 or more time controls you play somewhat often also helps you practice time management skills. If you ONLY play a very long time control (like classical or chess.com Daily Chess), then you may feel panic and pressure when you have less time remaining on your clock. Similarly, if you ONLY play speed chess, then longer time control games can feel like they take forever and trains you out of good patience. By having this mix of time controls, you can better practice how to play with different amounts of time left for the game.

I prefer to play classical games in the tournament , and play blitz online , which really tests player¹s reaction and tactical ability .