Hardest Endgame to Win

Hey everyone, I was just wondering what do you think is the hardest endgame position or type of endgame to win? I personally feel that in general rook endgames are very complex and hard to play because every tempo counts, especially when both sides have a passed pawn. Let me know what your least favorite endgame is to play!

mine are bishop and knight vs. king WAYTOOHARD

In general knight vs bishop is very unpleasant. I'd take bishop 9/10 times

yeah knight vs bishop is tricky, even with only 1 pawn on the board

king vs king

too hard to win

One of the hardest technical endgames is pawnless two bishops vs knight, when the weaker side is ideally placed.

But rook endgames have a large drawing margin, so they're not very stressful, usually.

Compare to something like queen and pawn when even if it's a draw, it's extremely hard to play correctly.

Most of them are pretty easy but the fact that there are so many makes it hard

Queen endings for sure. It can be almost impossible to calculate all the checks.

King and Queen against King and Rook is one of the hardest to win. It takes around 40 moves to get the ideal position, which isn't far from the 50-move draw rule. I heard a rumor that Walter Browne once had this endgame and failed to win it, but can't verify if it's true.

I agree completely.

Silman doesn´t even bother teaching it in his "complete" endgame course.

True, those are pretty hard

Some queen endgames aren't that bad, if you know the idea you don't need to calculate all of the checks perfectly. 

Queen endgames with a pawn of advantage, there just are too many checks

KNNKP are crazy hard to win.

It depends.

Hardest Elementary Endgame: B+N+K vs K is the hardest by far.

Hardest Pawnless Endgames: B+B+K vs. N+K, Q+K vs. R+K, R+K vs. N+K, R+K vs. B+K, R+B+K vs. R+K (The last three aren't even always theoretical wins; they are only wins in certain situations, so it depends on where the pieces are placed on the board.)

Hardest Endgames with Pawns: R+P+K vs. R+K, Q+P+K vs. Q+K

There are tons of checkmates, and I'm sure there are some theoretically won ones that are really wild, so wild that they become draws because of the 50-move rule and end up taking hundreds of moves to force a win. The ones I gave above are only the ones that are comparatively the most likely to happen in an actual game. These are the ones that I feel are very difficult or even impossible to win/draw, depending on which side you are playing and which situation the game is in (where all of the pieces are placed on the board).

I agree! What a detailed explanation

KQ vs KR is far more difficult. For practical purposes, perhaps KRP vs KR and KNP vs KN are the most complicated a human player can expect to play well. KQP vs KQ does occur in practice, but is way too difficult. Other exotic endgames, like KRB vs KNN, are far more complex, but do not have any practical relevance.

I agree