Someone please help me with endgames. I suck

AR - what about the skewer trick in the youtube video I posted?
If you look at the position of the black King - there's almost nowhere he's safe.
The only squares where he would be are c6 and c7 and b6 and b7 and a6.
And of course g7 and h7.
Otherwise he's losing to the skewer trick or losing a tempo by the attacking rook checking or the pawn just promoting ...
all of them game-ending one way or another.
So on 53 squares out of 60 he's lost with white to move.

Did you look at the Lucena position at all?

If your coaches are good coaches - they'll be happy to go over both the Skewer Trick and the Lucena position with you.
They probably know them both very well and would know they're key to understanding rook endings.

Having said that - while 'preparing the battlefield' is essential to winning whether in a game and when not playing ...
many might tell you that the essence of the game is to enter positions that both you and your opponent are unfamiliar with and then to reason out moves that are good enough and to do so efficiently enough.
In other words - ultimately you're on your own when it comes right down to the crux of the matter. The critical nitty-gritty of winning and losing.

Its essential.
You need to know how to stop that rook from checking you.
There are so many rook endings that any one of them is 'rare'.
If you don't realize about the Lucena position then you're less likely to trade down to it.
AR - try it.
Ask your coaches about the Skewer trick and the Lucena position.
If they dismiss either one as not mattering then you need to get better coaching.
Why haven't they mentioned these endings to you?
Well in fairness - they can't do everything at once.
You know your endgame isn't as good as your opening and middlegame ...
so - bring it up with them.

It came up many times in my blitz games.
Not as often as my weaker opponents playing their b-knight out in front of their c7pawn in the openings while I'm playing moves like d4 and c4 ... on many occasions I've been able to Crush in under 15 moves because of their awful opening strategy in doing so.
You also need to know the Skewer Trick so you don't fall into it!
Avoidance of mistakes is at least as important as exploiting them.

I suggest asking him about the Lucena position.
Some players can actually figure these positions out over the board ...
they could find the Skewer trick with no prior familiarity or even study of Skewers in general.
But having to take extra time to figure basics out could cost you many games.
Regarding the Lucena - some players might think: 'OK - I've got to triangulate my King back from my passed pawn and then be ready to interpose my rook on the file of the pawn when he checks me so that he gets no 'Nimsovitch rook' ...
And he could do that without knowing about Nimsowitch either ...
but good players study these basics so that they're ready to convert their pawn to a win.

There's also an endgame trick called "the sneaker"...

That ending in post #129 is beautiful.
I believe its also called 'the pawn breakthrough'.
I first saw it a century ago - literally ...

Now AR - that ending posted by blueemu will probably never come up in your games - but its what's called Instructive.
So is the Lucena position.

People might also tell you that N+ B versus Lone King is 'instructive' too.
My own opinion of that ending is 'No it isn't or too slightly'.
Perhaps some strong players would disagree.
But it is an intellectual exercise.
It has four phases.
1) Bring your King to the center to force his King out of it. Easy.
2) Force his King to the edge of the board. Not much harder.
You use mainly the bishop for that but the knight helps - including to produce zugzwang.
3) Force his King into one of the two correct corners controlled by the bishop.
That's the hard part. Even if you've studied Deletang's triangles and the W method - its tough. You could learn it and then forget it a few weeks later.
4) and Fourth - mate his King.
Your King and bishop and knight combine to make the bishop's limiting diagonal as confining to the other King as a rook would effortlessly so confine.
I look at it maybe once every ten years !!
But I think its mainly for 'aesthetic' value if that's the right word.

You do that in a lot of different 'Lone King' endgames.
But that's not the Hard part of N+B versus LoneKing endgame.
Suggest you ask your brother about the Lucena position.
I'd be curious to know his reply.
I also thought of this - you indicated you had some kind of weakness regarding zugzwang.
So I thought of: In the extremely fundamental pawnless ending of K+R versus LoneKing ... could the side with the R win if the other side had an option to not move his King? With a Queen - yes. But checks necessary to force him to the edge in that case.
With the rook - checks also available - but I'm thinking LoneKing would just dance round and round the center a knight's move or so from your King.
Haven't tried it on a board yet.
Got to log off now.

Watch this video:

https://youtu.be/soFjWrTVYKU?si=hePQd78tO4uzIaWb

and request access to his weekly training program. He has lots of ideas for endgame training

With a 1900 rating?
Is that a USCF rating? chess.com blitz rating?
What rating?
By the way its pronounced loo-Seena position.
If its not pronounced right he may not recognize it.
Luis Lucena was a chess great of his time - which was about the same time as Ruy Lopez and his chess opening (stayed #1 opening for ever so long) and Cristoforo Colombo (often referred to as Christopher Columbus) who discovered America.
Luis Lucena and Ruy Lopez were both Spanish but CC was Italian.

Have you got a USCF?
I added to my post #139 regarding how to pronounce Lucena and who its named after.