Standard endgame chess positions which are helpful to learn Is there a list of standard endgame chess positions which a player can benefit from learning? By this I mean that any player should know how to play KQ vs K, KR vs B, KP vs K (win if it winnable and draw when it is not). 

Then it goes KBB vs K, KRP vs KR and then on higher level KQ vs KR, KR vs KN, KBN vs K. These are just some of the end-game positions which might be helpful to learn.

Do you have other positions which could be helpful (and may be approximate level when it makes sense to learn them)?
For sure KP mixes like KP vs KP, KPP vs KP etc: learn to count moves to promotion, study opposition and zugzwang.

Later KRP+ mixes: like KRP vs KR till KR4P vs KR3P are all quite common, far more relevant than say KBN vs K, not easy though, especially 4 vs 3 pawns.

A bit less common KNP+ and KNB+. still relevant.

Finally endgames where one side has a piece and the other only pawns: this are quite common at lower levels.