general view on this is that blitz or bullet ( 5 or 1 minute game) is not helping to improve your chess skills.
I tend to disagree: blitz can be very good to train tactics:
forks, sacrifices, x-ray attacks etc.
But if u want to improve your positional style and learn more bout imbalances in a position long games are better.
I think recognizing imbalances is one of the most important parts of analyzing and in makin decisions over the board.
most important imbalances are:
- King safety and placement
- Pawn structure
- Pawn distribution (how many pawn islands)
In a long game you can ask yourself the question where your position is different from your opponent in these factors.
for instance: space: If your position is cramped,its usually wise to exchange some pieces to create more room for the others
other example: when you are offered to exchange queens its usually a good thing to find out whose king is better protected, if your opponents king is all open, its usually better to keep the queens on since its a strong attacking piece.
I'm totally off topic, but moral of the story is blitz is nice to train and keep up your tactical skill but to understand the game deeper long games are required.
I hope this helps you a bit