i feel like I'm suddenly bad at chess, help

Review the theory of openings and your reviews the errors and successes of your games. Basically you have to study openings again. The problem is that you are playing by act and reflex which caused you to acquire bad habits, that happens when you play by memory that is distorted from what the true theory is. So that the same thing does not happen to you, learn the opening for its concepts and why each movement.

Every time you see that an opponent makes you a variation that goes out of your theory, check after finishing the game if the "novelty" is a mistake or a reasonable move and how to punish in case it is a mistake. You must learn from each of your games, or else when you play you will go into automatic mode and each game you play will create a subjective distortion in your mind that makes you play bad moves that you think are good moves. That's the biggest problem with playing a lot of blitz and never reviewing the games you play.

Look for courses of the openings you play, the biggest mistake of the players is that they feel very safe in openings that they think they master, you have to study different lessons (start with the free ones on YouTube), review them, compare with variants of the chess engine and keep reviewing. The process of studying openings does not last three days, nor a week, nor months, but years to study each variation, line and sub-variation of the same opening and be a specialist in punishing each error can take at least two years.

If it seems too much to you and you are not interested in studying chess so much, then relax and do not take it so seriously. You don't have to stress over something that you have no interest in having a high sporting level, if you don't have aspirations to dedicate yourself to chess, don't bother knowing too much or get frustrated by being bad at playing. Better dedicate that time and discipline to what interests you the most and you will be very good at something if you are willing to study in detail. You can't have everything, you have to choose what to spend your time on.

man, all that is definitely a lot, but I'm ready to do whatever it takes. I'm truly interested in chess and it is literally my new year resolution to be a significantly better player than i currently am, when i look back at my games at the end of the year. i want to see a massive difference. everything you wrote is really going to help me a lot because i never looked at openings that way. can you also suggest me a solid opening that i should study and try to master? i like to play intresting and attacking chess. thanks  

Actually if you play 1.e4 you are already projecting a preference for aggressive play. Gambits are overrated (not that you blindly underestimate them), it's better to learn how to play well against gambits than play them. If you play the Italian opening, continue with the Italian opening and if you want variety, go for the closest thing to the Spanish opening. All openings have their advantages and disadvantages (speaking of recommended openings and except for those that are not recommended at a sporting level), you do not have to despair and leave an opening that you have been playing for a long time, as long as this opening is totally correct.

In any case, study the openings so that you don't complicate yourself too much, go step by step, you don't want to know everything at once, simply because you can't. It begins by mastering as well as possible an opening with white and a system for each defense and each variation within a certain defense. Get the idea that your main opening is your only opening, the guico piano is not a bad opening, but you have to look for updated sources as some variants have been disproved and/or improved. The simpler line, play 4.d3 to castle and then play 5.c3 is also good and you can stick with that line if you want. The idea is not to change openings over and over again without mastering one first. It is better to play one opening and play it well than to play several and play them poorly. Do not be intimidated by a variant that causes you problems, that is solved by studying and improving.

The aggressive style is learned by improving your tactics and studying model games, you need to master the tactical issues and also the specific plans that allow you to reach situations where the attack can be executed in a coherent way with the position. Knowing tactical issues is essential to better understand attacking games and ideas such as giving material in exchange for time (pawns or pieces).

Considering a better defense 1...e5 vs. 1.e4 , if you want something different try caro-cakann defence, although it is more profitable to wait until you have 2000 rating before playing it (there are many white attack plans you should know neutralize). A defense against 1.d4 can be the Slav Defense or the Queen's Gambit Declined. Choose the one you prefer, but try not to be indecisive and stick with one; In any case, you could first study a scheme where both converge in a transposition, there are many games that from a certain position you don't know if it started with one defense or the other. Against other less frequent things you can just play 1...d5 as well, but against the English opening consider whether to choose 1...e5 1...Nf6 or even 1...e6 followed by 2...d5. In any opening and defense there are very calm lines that look boring, don't always be discouraged by that, much less if you really like the opening you play.

You should also study endgame theory, if you don't know enough about endgames then you will be inherently bad in any opening you play. Start with the most basic of the endings and go dominating little by little; first study basic checkmates with each piece against king, then study pawn endings, follow rook endgames (these things are the fundamentals to start understanding endgames). What follows is understanding bishop endings, bishop vs. knight, knight endings, queen endings, minor pieces vs. rook, and pawns vs. minor pieces. Studying endgame theory also takes a long time, and there is always more to learn no matter how much theory you know.

Sometimes it will be necessary to break out of comfort and look at other openings and defenses, but make sure you stick with one opening for a long time (try not to play different openings for more than 15% of your games). Playing outside of your comfort zone causes you to have clashes with your knowledge, thus you discover defects and virtues that you did not know you had (as happened in your case when you switched to guico piano). But do not despair wanting to suddenly transition from one opening to another, keep playing what you know how to play best and when you master it really well and know the basics of tactical issues and endgame theory you will have a better ability to expand your openings.
As long as you don't feel stuck or bored, keep playing 100% of your games with your main opening as if it were the only opening there is.

If you're going to stick with one opening and defense for a long time, make sure you don't choose openings that are factually correct. Questionable or bad openings work in your favor if you learn to play against them (look for the most recent sources possible, old analysis can make you play very bad variations).
You will win many more games against flawed attacks (like stafford gambit for example) if you know how to play against them even with little study, than the few surprises that can lead you to lose.e. It begins by mastering as well as possible an opening with white and a system for each defense and each variation within a certain defense. Get the idea that your main opening is your only opening, the guico piano isn't bad, but you can also stick with 4.d3 followed by 5.0-0 and then play 6.c3 (or swap between 6.Re1 followed by 7. c3 ); but if you are playing the queen knight on c3 in the italian opening, better stop playing that, it is very inflexible (the queen knight is better on d2).

Make yourself a folder of pgn files organized with more folders (folders inside a folder called for example "italian opening" ). For example, you can name each variant in one folder and the deviations in other folders with a corresponding pgn file. This way you will be able to better study and review the openings, each line and subvariation, as well as each rare variant surprise of your opponents. You can call the lines by their names, but it is easier to put the corresponding number and movement of the deviations (especially do it like this where the names of the players go when you save the analysis, as if the variant were a player). Put the names in the folders, but in the pgn files just put the moves (or put both, but never stop putting the moves with the move number, for example something called "2...Nf6" the petrov defense) .

Try to be flexible when studying openings, final tactics;
Don't force yourself too much to study everything at once if you don't feel comfortable, you can spend a whole week just studying endings or tactics, a whole week or a month studying openings. Or you can combine a month of studying openings combined with endings, openings combined with tactics or tactics combined with endings. If you can adapt to study each thing by days of the week or schedule, it will be fine. The idea is that you study everything efficiently, if you separate each thing by weeks or months, you have to take a week or two to review everything combined as best you can, so that your mind can connect ideas. Also, for example, take a week or two to study only your games or the GMs (or a day or two each week), if you take a whole week or more to study games, always combine that with reviewing a bit of endings and maybe tactics ).

Chess Openings Resources for Beginners and Beyond...

https://www.chess.com/blog/RussBell/openings-resources-for-beginners-and-beyond

https://www.chess.com/blog/RussBell

If you've got a tournament coming up in three days, then the LAST thing you want to do it to try and stuff your head with unfamiliar lines. Jesus, what a dumb idea.

Chess preparation takes time and focus, and if you've only get three days, you should concentrate on non-chess preparation instead.

Spend the time preparing yourself mentally and physically. Get plenty of sleep, and eat well. Relax. Try to detach yourself from your anxieties. Center yourself.

Do something to build your confidence and to set the mood for the upcoming tournament. One suggestion is to play over some of your own games that you are proud of or happy with.

To address your concern about the sudden slump in results on attempting to master a new opening system: This is perfectly normal. When a student learns some new concepts... and especially, if they are exposed to several new concepts in a short period of time... they will struggle to integrate these new ideas into their existing playing style, and for a period their results will tank even in positions that they SHOULD be playing properly.

Perfectly normal. Don't worry about it. Just focus on integrating the new material into what you already know.

That's as may be, but NOT three days before a tournament. "Cramming for exams" is not good for your chess.

Meow indeed.

He is not the first to ask what to do 3 days or a week before a tournament. You just have to tell them that if they want to study openings, do it patiently, start with one in particular and that if they really want to try it, it will take them years and not three days. Nobody in the comments has told him what to do three days before a tournament, because the only thing I could say to that is that he is rested from the day before and things like eating healthy, exercising and sleeping well. In three days no one can learn a solid opening and all the principles of chess, a "solid" opening takes time too, it's contradictory for you to tell him not to listen to opening advice when you recommend a solid opening that he probably has to learn from scratch ( in three days).

hi everyone, i recently started studying the guoico piano opening. you all told me to learn one perticular opening and play it everytime, that's what I'm doing but a question really bothers me. what if i can't?? like what if i decide to play guoico piano and black goes for something fancy like scillian, french or caro kann? i just can't play the Italian opening against them the same way I'm learning the theory. i dont know if this question seems dumb but I'd really appreciate if you guys could answer it and clear my doubt. :)

That is the problem with the openings, you also have to learn to play against different defenses and if we talk about the Sicilian defense you will have to learn against different variants.

You mentioned that you would like to play an aggressive style, so believe it or not, the fact that your opponents play Sicilian defense, pirc defense among others, you will like it as you learn because you will discover attacking ideas that you can take advantage  (don't worry if you want to play positional, you can also play like this by playing 1.e4). In any case, continue learning the guioco piano opening and improving it, against the other defenses learn the minimum and apply concepts and strategies that you can check if they fail or succeed according to your experience (don't forget to review your games after playing, review every 5 or 10 games can be). He also sees exemplary games against the other defenses, classic games in particular, and later it will be better to see comptemporaneous games.

I recommend you learn the most theoretical against the other defenses, first the few movements, so you will have something in the meantime. That combined with exemplary games will help you understand some important details. When you already know enough about guioco piano, you study how to play against another defense in particular, I recommend you take into account how regularly you run into those defenses and also how much difficulty they give you to prioritize which theory to study more specifically.
In the process of learning how to play against another defense, try to review what you already know about guioco piano from time to time (also if you always play it that will keep your memory fresh).

I know I didn't mention this at the beginning, but if you think about tournaments you have to take them as a means to accumulate experience. When a tournament comes around, the main thing is to be in good physical shape, so a moderate exercise routine will do you good. Tournaments are to play what you already know how to play, to put yourself to the test; tournaments also count as training and learning, so don't be afraid of tournaments. The competitive environment of tournaments can motivate you for future tournaments, don't forget to learn from every game you play.

In the first place:

This advice that you've been getting, to pick ONE particular opening and play that, is not nearly as clear-cut or one-sided as people like to make it sound.

First, you should decide which is more important to you... (1) Having fun playing chess, or (2) Beating a same-level opponent, or (3) Improving your game and becoming better at chess.

If you picked #1 (Fun), then just play whatever leads to positions you enjoy. That might be a single opening, or it might be trying something different in every game.

If you picked #2 (Beat your rival), then yes, there is an argument in favor of a narrow specialization in choosing your openings.

If you picked #3 (Improve your play), then I feel that it would be a mistake to specialize too much, because you will probably learn more and learn faster if you are exposed to a variety of positions and plans instead of the same limited set each time.

To answer your question about what to do if the opponent avoids your prepared line... just make good moves. Develop your pieces. Control the center. Don't give stuff away. Find a safe-ish spot for your King. Then come up with a plan.

If you're not sure how to come up with a sensible plan, read the first two or three pages of this thread, and play over the sample games:

GM Larry Evans' method of static analysis - Chess Forums - Chess.com

Centre, attack, develop. This is the CAD formula.

Go back to c3. John Emms says it's okay.