Endgame Bootcamp 18

In contrast to the prior Bootcamp, where we have a clear plan for White with a plethora starting moves, Black has one move to start their path to victory.

8/1pR5/4k1p1/p7/P1pP4/4K3/1r4P1/8 b - - 3 41

Things to note:

Black has one more pawn than White. When we count pawn islands, Black has two and White has three.

Most of Black’s pawns are on the Queenside.

White’s King has already approached the center of the board, with pawns on both sides.

The Black King cannot immediately step to their hanging (undefended/unguarded) c pawn.

Both rooks are hanging.

Ideas:

We want to keep our single pawn advantage and coordinate the King and Rook to assist the queenside pawn island.

Black has to navigate correctly to get to their Queenside pawns, but once the goal is achieved, White can't stop the promotional path.

Unfortunately the immediate Kd5 allows equalization after Rc5, King move, Rxc4. Bye bye pawn advantage.

You wouldn't want to try the move like b6 on an experienced player as they may spot g4! The only equalizing move.

Why is g4 so important to play immediately in contrast to Ke4?

After Ke4 Re2+ is Black's only win! Kf3 Rc2 g4 g5 Ke3 Kd5. Now White can't check with the rook on g5. White could have if g4 was played (g4 g5 Rg7 Kd5 and Rxg5+), Black is still not out of the woods in this Ke4 line: after Rd7+ Kc6 Rg7 Black must play Ra2. White can continue to delay Black's capture of the a pawn with another check, instead of immediately capturing the g5 pawn (Rg6+ Kb7) and can even play d5 rather than Rxg5, but Black will still play Rxa4 either way and their c pawn will become a hero.

So how do we maintain our pawn advantage and not let White equalize?

Rb4!

Defending the c pawn, as well as maintaining defense of the b pawn, while also threatening the a pawn!

White has options, and Black has responses to each of them. Try to figure out what you'd play as Black if white plays either of these candidate moves: Ke4, g4, g3, and Rg7. Hint: Most of these allow Black one winning move. We will only cover Ke4 for this post.

Ke4

Black's only move: Kd6!

If White plays Rf7 followed by Rxa4 Rxb7 c3 Kd3 Rxd4+ because White must take the c3 pawn.
You also reach this idea with: Rf7 c3 Kd3 Rxa4 Rxb7 Rxd4

Rather than Rf7 White could play Rg7 and force another only move for Black, the one we have already touched on: Rxa4!

The appropriate time to capture on a4, whereas earlier would have lost the advantage.

Instead of Kd6: Rxa4 Rxb7 Ra2 Rc7 Re2 Kf3 Rc2 Ra7 and Black loses a pawn eventually.....

Black had to play Kd6 to force the White rook off the c file before capturing on a4, to ensure the White rook cannot become active on the Queenside.

After Rxa4 White can maintain sharpness with: Rxg6+ Kc7 Rg5 b6 Kd5 c3 Rg3 Ra3 Rg7 Kb8

With the exception of c3, Black had to make those moves to maintain the advantage.

Now Black can tuck their King next to its pawns, avoiding immediate checks by White's rook. Black also has the ability to take the first rank with their Rook before White can. White would love to get their first and stop the threat of c1=Q. Lastly, if White tries to get behind Black's c pawn, then the other pawns (a and b) start rolling towards promotion, or if Black positioned their rook on the first rank then Rc1 suffices.

Example continuations:

Rh7 Ra1 Rh8+ Kb7 Rh7+ Ka6 Rc7 Rc1

Rg8+ Kb7 Rg7+ Ka6 Rc7 (a4 or b5)

After Rxa4 White can also respond with: Rxb7 you should already know what Black plays here....c3! Kd3 Rxd4 Kxc3 Rg4!

We also achieve this idea if Rxa4 g4 c3 Rxg6+ Kc7 Kd3 Rxd4 Kxc3, except Rg4 is not possible so Black places its rook on one of five safe squares.

Congrats on making it to the end of this Bootcamp. See you next time!