There are principles that help when playing chess as I learned watching some YouTubers:
- Develop your minor pieces early in the game (bishop/knight)
- Castle
- Connect the rooks
- Put pieces in a way they are protected by other pieces, so you don't blunder.
- Don't put out queen to early or make heroic attacks with 2 pieces at the beginning of the game.
- Don't start pushing pawns like crazy before you've developed. Especially pawns in front of the king while board is still crowded by minor/major pieces. I think I've only lost a single game where opponent pushed pawns like crazy while leaving rest of the army behind.
- Watch out for ways how opponent can check you and do harm.
- See what forcing moves you have. Look for 1. checks and 2. captures.
- You don't always have to defend piece that is being attack - you can be more aggressive and make a thread yourself by advancing some other piece.
- To take is a mistake - you don't always want to take opponents pawn or piece as it can help develop them/put another piece on a more active square. Or it may help open up an open file for a rook, tldr makes opponent pieces more active (active means pieces cover more squares). You may sometimes benefit of enemy capturing your piece first and you recapture by leaving some file closed/blocked by pawn.
- Usually there is little calculation needed in the opening. GM Igor Smirnov also mentions that he doesn't always calculate. And he doesn't calculate what happens when opponent pieces go backwards, usually calculates what is the biggest threat opponent can make. And it can be beneficial to calculate just 2-3 moves ahead.
- Try to see what your opponent wants to do
- You must have some kind of a plan - why do you want to put piece on that square? Not just put it there because you have to move and on the next move that same piece is being threatened with, say, no defenders.
- Jumping in with the knight deep into enemy territory without a way to back out may cost you a knight.
- Putting a piece on a square that opponent can kick you out on next move maybe just looses tempo if the goal is not to reposition your piece or there is another thought to it.
Anyways, knowing all of this I'm only 800 rated. I blunder alot. Or I have a great advantage until I make it to the endgame where I loose. I also come to realization that one must remember / know lot of stuff to be good at chess. I thought my logical thinking is strong, but yeah, I don't enjoy the skillset needed to become good at chess.