How blitz and bullet rotted my brain (don't let it rot yours)

I am a far, far worse player than you are but I still feel I can say something worthwhile. You identify your three issues (in classical chess) as: tactics, time management and evaluation. I would say that there is just one problem there: time management. Fix that and the other two will disappear. There are plenty of top flight players who excel at both blitz and classical (e.g. Carlsen and Nakamura).
I don't think blitz games are your problem, although going cold turkey on them will be an interesting exercise. I think you may just be struggling at switching between the different needs of the different time controls.

I can totally relate. I've gotten into chess more seriously about a year or so ago at age 52, and I find blitz to be so much about quick pattern recognition and cheap tricks that it's a different game.

I think that if you simply stop playing bullet / blitz for a while and get back to practicing tactics, playing long games and most importantly analyzing every game, you will simply get back on the right track. I think what you describe is fixable, rather than being irreversible.

With all due respect, isn't stagnation expected at some point? Not sure it's necessarily because of blitz and bullet online. Just happens to people.

Thanks for taking the time to write 📝 and share this, liked the points raised on:
👉 tactics
👉 time ⌚ management
👉 evaluation of a position

Thanks for being open with your experience, it will definitely help others.
You're accurate with the cause, effect & remedy.
As you've already identified, sharpen up your Tactics with T.T. etc*, probably best to stick to your upcoming tournament time controls & Daily allowing deep self analysis to find your best lines/ best move.
Once game is finished then an overall analysis, improving/ testing any weaknesses.
You could also ask your fellow master peers for advice/ tips, e.g. ask @Ginger_GM, who for sharpening up your Tactics recommends:
*Blunders and Brilliancies: https://www.chess.com/blog/Ginger_GM/five-chess-books-that-have-helped-me-become-a-grandmaster

+++++ A great post OP, I have noticed the same at my meager level, but could not explain it half as well....when I stopped playing as much blitz and bullet my daily rating went up.

this is my 2nd favorite chess related post since
https://www.chess.com/forum/view/general/top-secret-method-for-chess-improvement-that-they-don-t-want-you-to-know-about
i've become a chuddog fan :-)
hope nothing happens to him, though the last person i was a fan of, the esteemed chessmate fm, got removed from this site :-(
I think that if you simply stop playing bullet / blitz for a while and get back to practicing tactics, playing long games and most importantly analyzing every game, you will simply get back on the right track. I think what you describe is fixable, rather than being irreversible.
That's exactly my plan and hope. I definitely don't think it's irreversible. From a neuroscientific point of view, it's been shown that adult brains are much more plastic and amenable to change than we used to believe they were. And I don't think I've topped out how well I can play. I believe I can get better, not just worse.
From a practical point of view, I got back to the tactics trainer last night. Woo boy... I am rustier 'n the ol' wheelbarrow at my grampaw's farm. [There are no farmers in my family.] Seriously, though... First thing I did is drop like 20 tactics rating points (~2450 to ~2430). I kept choosing the wrong solution, and only on the second try getting it right. And it would be take me a while to understand why my first solution was wrong. For one of those puzzles, only today I finally got why my first attempt was wrong.
But then, I felt the cogs starting to turn. I was doing the puzzles very slowly, but thinking about each one until I got it. Trying to get rid of the habit of making superficial decisions. Did some more puzzles this morning, and I'm feeling less rusty. I'm doing them slowly, but correctly.
Thing is, I play in a highly tactical style. If anyone cares to look through my games on here, you'll see that most of my wins involve attacks, sacrifices, etc. But I think a lot of it is superficial, full of mistakes by me and my opponent. I wasn't getting punished for my mistakes in blitz and got into bad habits.
I've been analyzing some of my games from my recent tournaments, where it's not clear what I missed. But when I'm blundering left and right, there isn't much to analyze. Like in one game on Saturday, I missed a knight move by my opponent. A very obvious and simple knight move. Didn't see it until he actually played it. Like, "oooh, that's how the horsey goes!" So yeah... need lots of tactics training.
this is my 2nd favorite chess related post since
https://www.chess.com/forum/view/general/top-secret-method-for-chess-improvement-that-they-don-t-want-you-to-know-about
i've become a chuddog fan :-)
hope nothing happens to him, though the last person i was a fan of, the esteemed chessmate fm, got removed from this site :-(
Thank you, I appreciate that. Seeing how I don't cheat or post anything offensive or abusive, I don't see why they would kick me off the site.
If interested in reading more of my chess writing, I have a column in Chess Horizons magazine (http://www.masschess.org/chess_horizons/chess-horizons-archives.aspx) starting spring 2016. I also had the cover story (co-authored) in the Sept 2017 issue of Chess Life, but that's probably available only to USCF members.

I've been analyzing some of my games from my recent tournaments, where it's not clear what I missed. But when I'm blundering left and right, there isn't much to analyze. Like in one game on Saturday, I missed a knight move by my opponent. A very obvious and simple knight move. Didn't see it until he actually played it. Like, "oooh, that's how the horsey goes!" So yeah... need lots of tactics training.
Yeah I understand how you feel. When you blunder like that or have a blind spot, it kind of feels like there's not much to learn from the incident other than "don't fk up like that again". But that's not the whole truth.
Firstly, we tend to blunder more in certain situations and positions. This could be due to - 1. having a worse position, 2. being in an unfamiliar or unstylistic position (open vs closed, sharp vs quiet for instance) and last but not least, factors outside of the game (Being tired/troubled, not concentrating, insecurity/anxiety etc). So I guess what I'm saying is, even though it seems like the blunder "just happened", it is not necessarily so the case. There possibly could have been nuanced precedents to the blunder.
Second, blunders can also be analysed and worked on. As silly as it sounds, missed a knight move? Study the knight - explore opening with interesting knight moves, practice tactics and endgames with knights. Missed a simple pawn move? work on tactics involving pawn pushes, openings with pawn gambits and deeper understanding of strategy regarding closed positions with certain pawn formations. Pawn endgames too, of course.
I could go on but you get the point. Even the silliest blunders and blind spots can signal a specific point you need to sharpen.
Lastly, once you really get in "hot shape" - after a lot of tactics practice, learning new openings, working on endgames, studying masters' games and analysing your games (Do all of these! never focus on just one aspect when studying. It can lead to stagnation as well), you will simply be sharper in your games. More intact with yourself, making better moves and having a better vision of the whole board.
Good luck, if you really want to get better I have no doubt that you can.
I'm going to relate my experience of how online blitz and bullet has, in my self-analysis, harmed my chess game. I'm a 2400+ US senior master and FIDE master, but this may apply and be helpful at all levels. I'm not sharing this as a typical forum confessional, but because I think it may help others.
Starting a few years ago and up to ~ a year ago, I was steadily improving. I went from a low (not all-time low obviously, but multi-year low) of like 2370 to ~2430, getting the highest rating of my life. I got rid of fear in my game and gained a decent killer instinct, winning games positionally and tactically. Mind you, this is in my mid-30s, which is a late age to improve.
But, for the past year, I've been stagnating. After every tournament, my rating was staying the same. I started giving up upset losses and draws. Yesterday, I played in a local tournament that was a complete disaster. I went 2.5/4 against opponents rated 200-400 points lower than me, and that's actually much better than I deserved. The way I played, it should have been more like 1.0/4.
First question is, what has happened to my game? First and foremost, I've gotten worse at tactics. Yep, the t-word rears its ugly head once again. You know how every forum post on here on "how should I improve?" is answered with "tactics, tactics, tactics"? Well, it applies at every level. My positional understanding is still as good as before, but I'm missing tactics left and right. And it seems to be getting progressively worse. Second, my time management has gotten terrible. I'm getting into time pressure nearly every game and have blundered or lost on time repeatedly. Third, my ability to objectively evaluate the position has also gotten worse. I'm being overly optimistic and missing resources for my opponent, and sometimes overpressing a drawn position and losing. There may be more problems, but these are the most obvious ones.
Second question is, why? Well, as it happens, a little over a year ago I joined chess.com, and quickly got addicted to the live games feature. By which I mean blitz and bullet (I'll just refer to it as blitz). I've playing way, way too much online blitz. As it's clear that I've gotten worse at chess in that time, and nothing else in my chess-related life has changed, I don't think it's a coincidence.
Here are the excuses I gave for why it's OK to play blitz: (1) It's still practice of sorts and keeps me warmed up and sharp. (2) It's a good, quick way to test out opening ideas, being able to trash ones that suck without losing an actual tournament game. (3) It's also a good way to practice endgame technique.
But here are the problems blitz has created: (1) It's messed with my ability to manage time well in slower time controls. Sometimes I move too fast and miss my opponent's resources. Other times (more often) I leave myself too little time. The point is, getting into a habit of moving fast all the time has made me worse at spending time intelligently. (2) It has made my game more superficial. This is where the tactics thing comes in. In blitz, you can get away with mistakes way too often. It makes you lazy at calculating and evaluating. I often play stupidly in blitz, and don't even get punished for it. I also don't have time to evaluate deeply in blitz, so I don't. And now I'm missing stuff left and right in slow chess. (3) It's not really good practice. I've spent way too much time playing against weak players who don't challenge me. A very obvious outcome of this is I've gotten worse.
To be clear, I'm not blaming chess.com. It's a great site. I'm blaming myself.
So, my plan is to go cold turkey. I'm going to (try to) stop playing bullet and blitz on here. I'll still be available for lessons, and I'll keep playing a bit of daily chess, but I have to get rid of this poison that's rotted my chess ability.
To those seeking to improve, I would also suggest minimizing blitz. Play slower time controls, get into the habit of digging deeply into a position and finding the best move. This is not new and has been said many times by many people. But I thought sharing my experience as an advanced player and teacher may be helpful. Best of luck to everyone.