why lichess choose puzzles from rapid and classical game only?

title

why?

if you can update a feature that puzzle can be chosen from blitz and bullet games too please.

That's not true, I've encountered many puzzles from blitz and bullet.
The generator software doesn't care of the time control but only of the position.

Yes, the reason more puzzles are chosen from there is because players have more time to think and to find a good move, which increases the chance of puzzles generated there.

I have one more question, what is minimum elo to appear to the puzzle?

Pretty sure you can get a puzzle from your game at any elo, whether you are 700, or a 2800. it doesnt matter

There are very few puzzles from low-rated people

Here's one between an 854 and 926. I've never seen another one close to that rating.

lichess.org/training/jucpS

@Deadban, as I understand, there are puzzles from biliz and bullet games, but only if at least one player from that game has a title. And there is no such restriction for Rapid and Classical.

@VelociraptorRex said in #7:
> @Deadban, as I understand, there are puzzles from biliz and bullet games, but only if at least one player from that game has a title. And there is no such restriction for Rapid and Classical.
I just opened a random puzzle from my history and guess what it's from bullet and guess what none is titled. lichess.org/training/JiFaW

@Deadban said in #8:
> I just opened a random puzzle from my history and guess what it's from bullet and guess what none is titled. lichess.org/training/JiFaW

Whoops, very strange. I am sure a while ago I could see puzzles only from [semi-]titled Blitz and Bullet. Same with 'puzzles from my games' tool: I have seen less puzzles and only my games against titled players, or from Rapid/Classical time control.
But now things are different, really! I was wrong :)