Two subset folders of Lichess puzzles

[Lotus340]

Recently, @FritzUser downloaded the entire Lichess puzzle database and sorted it by rating, putting it on this site as one very large pgn file. That was a great piece of work and we should all thank him for it.

Looking at that file can be rather daunting however, because how can anyone cope with 3.3 million puzzles? They are overwhelming in their number.

That's one of the advantages of a tactics book: there is a certain amount of puzzles (400, 1,000 or whatever): we do them and we get a sense of accomplishment on finishing them.

Thinking along these lines, I decided to create two smaller subsets of Lichess puzzles. I first split his original 896 mb pgn file into 200 files. Then I took the first 1,000 puzzles from each file, starting at the lowest 400 rating and going up to the highest rating of about 3000.

The result is a bank of 200,000 puzzles which go steadily from low to high in rating. It's a large enough number to be useful for a long time, but it's easier to manage and to share with others.

The second folder is another subset. After I took the first 1,000 puzzles from each file, I then took the next 100 puzzles. There is no overlap between the puzzles in the two files, because they come from different "slices" of the pgn.

The result is a series of 20 pgn files which in total contain 20,000 puzzles. They are quite manageable in size and go up the ratings much more quickly than in the first file.

So a person can start where they like and move up in puzzle difficulty, finishing one pgn before going on to the next. This gives the necessary sense of accomplishment, just as if they were working with a tactics book.

So here are the two folders, contained in one compressed file (7.5mb size). Many thanks to @FritzUser for providing the original pgn file. I haven't done much really: my only claim is that I had some spare time available to work with that file and create these subsets.

Note: this WeTransfer download link is only valid for seven days. After that it won't be renewed.

https://we.tl/t-ME7qDUuuyd

[Lotus340]

Incidentally, other people are making selections of Lichess puzzles, sometimes for commercial purposes. I don't really agree with that, as the whole ethos of Lichess is that things are freely shared and available to everyone.

Martin Justesen, for example, has published a series of books of Lichess puzzles. His main claim is that he chose only the highest-rated puzzles. The books are USD10 for 500 puzzles.

Personally, I prefer pgn files because you can do a lot more with them, and I would not pay such an amount. But I suppose there may be a market for what he has done. There are 10 books x 500 puzzles each, so you would have to pay USD100 for 5,000 puzzles. You can see his book series here:

https://www.amazon.com/s?k=Martin+justesen&crid=85VHNYM8WF4C&sprefix=martin+justesen%2Caps%2C1446&ref=nb_sb_noss_1