How to use my passed pawn

I'm currently trying to improve as a chess player (who is not? ) and so far my analysis shows that I loose my games in the endgame. I'm currently rated at about 1350 in standard live chess on this site and even against players rated 100 or 200 points higher I can achieve a lead of 2 pawns in the middlegame, but I almost certainly can't bring it home in the endgame.

This position is out of one of my games where I played White and was leading with 2 pawns in material but up to this point I already lost one. Nonetheless I had a material advantage and the pawn was a passed pawn. So I think I was ahead and could win the game if properly played. Now following the rule "If you have a passed pawn, you have to push it" I decided to support the passed pawn with my rook by playing Rb1. And I think that this move lost the game for me, basically because my rook was out of the game, protecting my extra pawn. He started to attack my king with his knight and his rook and checkmated me some moves later.

Is my idea of why Rb1 is a mistake here correct? And what would have been a good move? How can I use my passed pawn to build some pressure? Ideally I would like to force him to use his material to prevent me from promoting, while I can freely attack with my pieces, that has to be the idea, right?

I did consider b4 right away, but I feared Rb2 from Black which would prevent me from supporting my pawn with my rook from behind. Behind is where the rook belongs to support a pawn for promotion, I guess...

It is frustrating when you can't convert your advantage into victories so I would really appreciate some help,

thanks, babigs

Can you post the actual game ... Rb1 sounds rather right at first glance PROVIDED there are no tactical shots your opponent can play and deserve attending to immediately.  

b4 does looks wrong as Rb2 pre-empts any hope of you playing Rb1.

Your g3 pawn is a target that he can apply two pieces (N + R) of force to, but that hardly matters when you are rolling your passer down the board with a rook behind it. Not even sure he can win the pawn as you can push it or look for tactical ideas of your own.  

You said his N + R hurt you ... I find it hard to believe that you got mated and it is LIKELY that you made tactical errors leading to it that you are not really focussing on as opposed to the questioning a key strategic idea (rooks behind passed pawns) that every russian schoolboy would normally play in his sleep.

Unless I see the game and the moves you actually played, I really don't think I'm in a position to label Rb1 as a mistake.

This is how the game ended. I totally agree with you, I made errors there. Is not centralizing my king the biggest?

Thanks again!

I think you had the right idea. There are other moves besides getting your rook behind your passer (37. b4), and they do seem to work better, at least initially, but it gets harder and harder to advance and support the passer with the rook from the side. In contrast, getting behind the passer makes things hard initially because the scope of your rook is so restricted until the pawn can push further down the board.

A few observations about this position:

+ If the minor pieces go off the board you win, so any exchanges are to your advantage.

+ Ideally you would like to reach a position where your rook is on b3 (behind your passer, let's say you've pushed it one square to b4), where it can simultaneously support your passer and your g3-pawn.

+ Your king is safe from immediate checks from the black rook on h3 and the back rank where your rook lies.

I added a variation to your line with some notes:

I don't think it's an easy endgame.

Thank you very much for your reply! It's very helpful for me!

You are welcome.

Unfortunately it turns out that Black can get at your king anyway in my line by using a threat to your rook as a jumping off point:

It seems to me that you just can't let the Black knight into your position, otherwise it just creates havoc. You've got three warring principles here:

1. Restrict your opponent's play

2. Rook activity is paramount in rook endings (active pieces, the other side of the coin to restricting your opponent).

3. Rooks belong behind passed pawns.

When your passed pawn is so far back, moving behind it contradicts the second principle, and in this case it's just too much of a disadvantage for your rook. This may be a rare example (caused by your knight being so distant perhaps), but I suspect that you need to keep this contradiction in mind whenever placing your rook behind your passer. For example, if your passed pawn is still on the second rank, and your opponent has a knight in place to block it from the third rank, would you place your rook behind it on the first rank. Only if it were under immediate threat, and even then it might be wiser to employ your rook elsewhere, perhaps to set-up a counter-exchange.

A line that might work, whereby you aim to restrict your opponent's knight, and force the battle to take place his half of the board, where your slow-moving knight is already stationed and where you might be able to manufacture a pin or fork off the Black king to effect an exchange:

Did I mention this is a difficult ending. Difficult, as well as educational, for you as well as me.

Wow, thanks again for your thoughts on that position. I didn't notice you wrote your last post 3 month ago, but with some time in between it didn't loose any of its helpfullness.

Thanks!