The Floating Square | Split Pawns vs Connected Pawns in the Endgame

In the endgame, every move counts.

Therefore, it’s extremely important to understand at a glance whether or not your pawns are able to promote.

I’ll detail how to understand at a glance whether or not you can start pushing pawns toward victory in a king and pawn endgame.

Table of Contents

How to Promote Connected Pawns

Connected pawns are the easiest type of pawn chain to promote. If we remember the rule of the square, it becomes easy to see why the king cannot capture both pawns on its own.

Once the king captures one pawn, the other pawn rushes towards the end of the board and gets promoted into a queen.

Promoting connected pawns vs a lone king

What you need to do is maneuver your king close enough to the pawns so that you force zugswang and the king has to give way.

Just like promoting king and pawn vs king, the king simply wants to navigate to the dream square. Because you have a second pawn, you always have an extra tempo to use, making this an easy win.

1. Kg3 Kd7 2. Kf4 Kc6 3. Ke5 Kd7 4. Kd5 Ke8 5. Ke6 Kd8 6. d7 Kc7 7. Ke7 Kc6 8. d8=Q

Of course this is only one way to promote the pawn into a queen.

It doesn’t matter how far away the white king is in this scenario because the black king can never capture the pawn on c5.

When the connected pawns are closer towards the center, this becomes easier to do.

The tricky part comes when your pawns are on the a and b or g and h files. This is because there are stalemate threats if you’re not careful.

Promoting Connected Pawns on the a and b or g and h files

[FEN “8/k7/P7/1P6/8/1K6/8/8 w – -“]

1. Ka4 Kb6 2. Kb4 Kc7 3. Kc5 Kb8 4. b6 Ka8 5. a7

Note that a7 is not a mistake, but it does require more accurate play for white to convert into a win.

The simpler Kc6 leads to white trying to occupy the dream square after …kb8 c7 etc.

In this situation, white has to sacrifice the h pawn or the win is never possible. Stalemate possibilities lead to white not always converting this situation, so it’s important to master the technique.

5…Kb7 6. a8=Q+ Kxa8 7. Kc6

At this point, it’s important to have a full mastery of promoting king and pawn vs king to understand why this is a win for white.

7…Kb8 8. b7 Ka7 9. Kc7 Ka6 10. b8=Q

Promoting connected pawns vs a Rook

While this article is about pawn endgames, it’s important to acknowledge the power of two connected passed pawns. If they are advanced far enough against a lone rook, one of them will always promote.

Even without a rook, white can still promote one of the pawns if the king is far enough away.

1. a7 Ra8 2. b7

And now after white captures on a7, the b pawn promotes with check. If the rook stays on the 8th rank,

How to promote Split pawns with the Floating Square Rule

Now that we understand how strong connected pawns are, what about split pawns?

This idea was called “the floating square rule” in Mark Dvoretsky’s Endgame Manual from an idea from A. Studenecki in 1939.

Split pawns are pawns not on adjacent files. They could be the a and c file pawns for example.

You may think that if the opposing king is close enough, he can capture both pawns without worrying about either promoting.

However, in many instances, split pawns protect themselves. That means that if the king ever captures one, then the other promotes, therefore the king is stuck bouncing back and forth between the pawns, and never capturing them.

[FEN “1k6/8/P1P5/6K1/8/8/8/8 w – -“]

1. Kf5 Kc7 2. a7

If Kxc6 then 3. a8=Q+ leads to victory.

There are some scenarios where the pawns protect themselves, and some when they don’t, and it all depends on the rank they start from. To understand this, you’ll want to understand the square.

The square technique for split Pawns

The key of this article is to help you to understand at a glance whether or not the pawns support each other or they don’t. If you can master this, then you can understand when you want to go into this end game and when you want to avoid it.

The easiest way to understand is based on the square technique for split pawns. This is a similar approach to the square for promoting pawns in this article because it has to do with drawing an imaginary line.

Credit for this idea comes from Starting Out: Pawn Endings.

Looking at the previous example, we can see at a glance it is a win if we draw a square. Start from the a pawn and trace a line to the c pawn. Based on the number of squares away this pawn is (2) build a square towards the promotion square with the same number of squares (2).

Note, when drawing the square, if the pawns are not on the same rank, then start with the more backwards pawn and trace the line to the file of the other pawn.

If the square is touching the promotion square on the 8th rank, then the pawns support themselves. White simply needs to waste a tempo so the black king must move, allowing one of the two pawns to promote.

With black to play, the pawns do not protect each other as the square does not reach the promotion rank.

[FEN “8/8/8/Pk6/3P4/8/8/7K b – -“]

1… Kxa5 2. d5 Kb6 3. d6 Kc6 4. d7 Kxd7

If we combine split pawns and connected pawns, we see a different outcome.

Because the pawns’ square does not reach the promotion rank, they do not support each other. At the same time, white’s king cannot leave the g1 and f2 squares or else the pawns promote.

The result ends up being a draw since neither king can capture the pawns. The drawing maneuver for white is to play Kg1 – Kf2 and for black it is to play Kb7 – Kb8.

If white tries to advance the pawns, black will actually win because the king can gobble up both pawns and then assist the f or g pawn to promotion.

[FEN “1k6/8/8/P1P5/8/5p2/5Kp1/8 b – -“]

1… Kb7 2. Kg1 Kb8 3. c6 Kc7 4. a6

4…Kxc6 5. a7 Kb7 6. Kf2 Kxa7 7. Kg3 Kb6

Example scenarios for Split and Connected Pawns

Let’s look at a few examples.

Examples When can a king can capture both pawns

The black king can capture both pawns with proper play, since the white king is tied to the connected passed pawns.

[FEN “8/8/1k6/8/P2P4/6p1/6Kp/8 b – -“]

1… Ka5 2. d5 Kb6 3. Kh1 Kc5 4. a5 Kxd5 5. a6 Kc6 6. a7 Kb7

Examples When can a king cannot capture both pawns

white wins without needing the king

[FEN “8/8/8/2k5/P3P3/8/8/7K w – -“]

1. a5 Kb5 2. e5 Kc6 3. a6 Kb6 4. e6

Show close and far distance pawns.