What Puzzles should I focus on?

Not sure if this is the right forum for this topic but I'd like to work on a major weakness in my play and focus on puzzles for a week or so on that one "theme", perhaps on another site that begins with L.

The problem is, I don't really know what my biggest flaw is. Should I work on mate in 2 or endgame puzzles? That's often suggested, but that generally isn't a concern for me. 77% of the time when a game does end in a checkmate, my opponent wins. Sometimes, there's nothing I can do. Unless there's a way I can escape my opponent's two queens and king with my lone king, there's no hope for me.

Thanks for any suggestions in advance. Feel free to analyze any of my rated games. If you think there's a common thread among a handful of them, that's probably an area worthy of study.

If you want my honest opinion it's not puzzles that you need, I had a look at some of your lost games and most have one thing in common, time left on the clock. I honestly think if you slow down a lot you'll win a lot more games, these are rapid games by the way. For example, in one game you had over three and a half minutes left on the clock yet your opponent had less than 35 seconds, I seen that in two different games, you might not have the best position but your opponent could blunder as they're racing the clock. In other games you missed multiple wins, if you want to play the puzzles I'd be looking at endgame play and trying to spot those missed wins.

#1
"What Puzzles should I focus on?"
++ All, and randomly mixed. In a real game nobody tells you what kind of tactic to look for.

"I don't really know what my biggest flaw is." ++ Analyse your lost games to know.

"77% of the time when a game does end in a checkmate, my opponent wins."
++ That means you do not look after king safety enough.

"Unless there's a way I can escape my opponent's two queens and king with my lone king, there's no hope for me."
++ When your lone king faces 2 queens, you have done something wrong before.

That definitely may be the case for Rapid. However, of the 4 Blitz games I've played, I lost by checkmate but if you look at the time, I'm racing to find a move before I'm out.

For example, in my 5|5 game against sarada143, my opponent has made very fast moves. I lose with 36 seconds on the clock, but sarada has nearly a full five! In another thread, I was asked to consider playing Blitz but I have the exact opposite problem with it as I do with Rapid. In Rapid, I forget how much time I have and as you said, I should slow down. In Blitz, I'm constantly trying to calculate good moves while my clock keeps ticking closer to zero. Should I stick with Rapid?

You may have a point, but I've lost one game recently in Rapid as I was out of time. Here my opponent has over 5 minutes and 35 seconds left when my clock runs dry in a 10 minute game.

#4
"Should I stick with Rapid?"
++ Yes, preferably 15|10.

I think you comment is very general but I wanted specifics so I'm afraid it wasn't very helpful. I've done as much game analysis as I can with a free chess.com account and even with the use of other websites, I can't seem to find a "common weakness". Perhaps you'd like to take a look at my games to offer me a better tip than tell me that I've obviously made a mistake if I let my opponent keep two queens against a lone king?

Thank you!

https://www.chess.com/stats/puzzles/cybermanking

It seems like that in puzzles you have the same weakness: you play way too fast. Instead of trying to solve the puzzle, you just make some move and hope that it works. There are a lot of examples where you make a wrong move in 9 or 11 or 14 seconds. 9 seconds, seriously? How is that not a completely random move?

Puzzles are meant to be solved fairly quickly. One of my most recent puzzles I attempted I finally made a move after 73 seconds with a target time of 16 seconds and an average time of other users at 46 seconds. I failed. From a few days ago, I solved a 2 move puzzle in 9 seconds. If it was a random move, then the the next move should also be random. What are the odds I did two random moves in 9 seconds and solved the puzzles successfully?

I don't know where you got that from, but it is wrong. Puzzles are useful if you try to solve them and calculate variations. (They are probably the best way to improve your chess skills.) However, they are not useful if you just make a good-looking move and hope that it works.

How do I solve puzzles beyond just going for the best move at first glance?

You list "candidate moves", which are practically all checks and captures. Then you look at them one by one and see whether they lead to somewhere or are they just nonsense. This is a slow and time-consuming process, and it does wonders to your chess.

Here is an example where there is mate-in-1 and you did not find it after "thinking" for 9 seconds:

https://www.chess.com/puzzles/problem/726424

Here is another mate-in-1:

https://www.chess.com/puzzles/problem/1633412

Here is another:

https://www.chess.com/puzzles/problem/1735276/practice

I think it's  better to solve just one theme in puzzles, for example last month I did 1000 checkmate in ones and my puzzle rush 5 minute increased by 10% when it had been stuck for years previously, this month I am doing nothing but anastasias mate puzzles, it's better to be good at one thing than a jack of all trades.

I don't play Blitz so I can't comment on that. Considering your last post to me I think that because your opponents might play fast you are thinking the same, correct me if I'm wrong, if you're not under time pressure don't be forced to play fast just because your opponent does. Try and calculate the best move you can while your opponents clock is ticking down, if you're struggling for time then maybe increase it for a while and see how you do, I think magipi is spot on, you just play too fast at times and hope for the best. It makes me wonder if someone is chasing you while you play, slow down a bit and I'm positive that you will win more games.

chess is a deep & complex game... far better to learn as much as possible.

great to improve your area of strength, but it's surely better for your game to focus on correcting known weaknesses to become a more universal player.

for an analogy, here's how i solve actual puzzles:

first, flip all the pieces the right way to SEE them;

next, separate the borders to create a framework;

after that, group the remaining pieces into colors;

finally, use the info provided to complete the rest.

flipping one piece over at a time & staring it down won't be quite as effective as a solving strategy.

fundamentally, chess skill is just a measure of how well you organize pattern recognition of strategic & tactical ideas into a coherent structure of thought.

(1)Memorize and practice the checkmating patterns. Once you are confident that you are good at picking up checkmates, you will see how your tactical vision rises and so will your rating (Hopefully). 

Checkmating pattern is the foundation of tactics. 

(2) Develop a habit of taking time for blunder check. 

This is one basic problem of almost all the players below 1400. They do not check for blunders before making moves. Take your time to think. Just stare. 

Tell yourself that it is okay to lose in time rather than lose in tactics. 

As long as you gave your best, losing on time is not considered an actual lose. This is a chess site, not an actual tournament. You are using this site for two purposes. Either for learning or for fun. Or maybe both. So, focus on learning from each game rather than winning. In the long run, you are the one who is victorious if you learn from each game. 

Always take time.

(3) Do not trade pieces if you gain nothing from it.

I have noticed you trade pieces easily. Trade pieces when there is pressure from the opponent or the position has become too complex for you.

Let's say queen and a rook from your opponents' side is harassing your queen. Trade your rook with their rook if possible. It will diffuse the pressure.