Teacher / Parent Answer Key

Endgames & Checkmates

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Ladder Mate

Teacher/parent key for Worksheet: Ladder Mate.

Worksheet Answers

  1. Prompt: Draw a “wall” on a board diagram and explain how a rook can stop a king from crossing it.

    A rook controls every square along its rank and file, so it can draw a wall the king may not cross.

  2. Prompt: In the mini-game, which rook is the wall and which rook is the moving rook right now?

    Answers vary by the position reached, but one rook must keep the king boxed while the other rook slides closer.

  3. Prompt: Solve each ladder-mate practice position and write which rank or file became smaller after White’s move.

    Practice 1: rank 6 becomes the wall. Practice 2: the box narrows again. Practice 3: Rb7 then Ra8 finishes the mate.

Model Line

  1. Rg6
  2. Kf8
  3. Rb6
  4. Kg8
  5. Rb7
  6. Kh8
  7. Ra8#

Practice Position Solutions

Ladder Mate — Practice 1

White to move. Find checkmate in one.

Solution: Rg8#

The rook on a7 already covers the whole 7th rank, so the king cannot step forward. Rg8 delivers check along the 8th rank, and with rank 7 blocked, the king has nowhere left to go.

Ladder Mate — Practice 2

Start the ladder. Move one rook to make a wall that keeps the king from coming down the board.

Solution: Rg6

Rg6 builds a horizontal wall on rank 6. The black king is still safe for the moment, but it has less and less room each turn.

Ladder Mate — Practice 3

The king is boxed in near the back rank. Slide the other rook so the box gets even smaller.

Solution: Rb6

The rook from a6/b6 takes over the next wall so the rook on g6 can stay ready for the finishing ladder steps.

Ladder Mate — Practice 4

Finish the ladder technique from here. Find White’s forcing sequence all the way to mate.

Solution: Rb7 Kh8 Ra8#

Rb7 leaves the king only one square. After Kh8, Ra8 is the final rung of the ladder and checkmates.

Queen and King Checkmate

Teacher/parent key for Worksheet: Queen and King Checkmate.

Worksheet Answers

  1. Prompt: Write one sentence explaining what the “queen box” means.

    The queen box is the area the enemy king is trapped inside because the queen controls the edges of that box.

  2. Prompt: Why is it important to bring your king closer instead of only checking with the queen forever?

    Your king helps cover the last escape squares so the queen can finally mate safely.

  3. Prompt: Solve the queen-mate practice positions and circle the one where a careless queen move could stalemate.

    The near-corner practice position is the stalemate warning; Qc5 keeps one square open, while the full line ends with Qf7#.

Model Line

  1. Ke4
  2. Kd6
  3. Qc4
  4. Kd7
  5. Ke5
  6. Ke7
  7. Qc7+
  8. Ke8
  9. Ke6
  10. Kf8
  11. Qf7#

Practice Position Solutions

Queen and King Checkmate — Practice 1

White to move. Find checkmate in one.

Solution: Qa8#

The white king on g6 already covers g7 and h7, so those squares are off-limits for Black's king. Qa8 checks along the 8th rank, and with g7/h7 covered and g8 controlled by the queen's rank, the king is trapped.

Queen and King Checkmate — Practice 2

Shrink the box with a checking queen move.

Solution: Qc5+

Qc5+ checks while taking away many center squares. The king is still not trapped yet, but the box is smaller.

Queen and King Checkmate — Practice 3

Your queen already has the king boxed in. Bring your king one safe step closer.

Solution: Kf4

Kf4 keeps your king safe while helping for the final mate. The queen keeps the black king from running away.

Queen and King Checkmate — Practice 4

Be careful: one queen move here would stalemate. Choose a queen move that keeps the box but leaves the king a square.

Solution: Qc5

Qc5 keeps control and still leaves Black a square, so the game continues. Avoid queen moves that trap the king without giving check.

Queen and King Checkmate — Practice 5

Finish the queen-and-king method from this point. Find White’s full forcing line to mate.

Solution: Qc7+ Ke8 Ke6 Kf8 Qf7#

First the queen checks from a safe distance, then the king steps up, and finally Qf7# ends the game with king support.

Rook and King Checkmate

Teacher/parent key for Worksheet: Rook and King Checkmate.

Worksheet Answers

  1. Prompt: Why can’t a rook checkmate by itself without its king?

    The rook needs its own king to cover the final escape squares. Otherwise the enemy king can keep slipping away.

  2. Prompt: In the mini-game, which edge is Black being pushed toward?

    Black is being pushed toward the back rank and then toward the corner.

  3. Prompt: Solve each rook-mate practice position and underline the move where the rook acts like a wall.

    Kf5 improves the king, Ra7+ builds a wall, and the final sequence ends with Rh8#.

Model Line

  1. Kf5
  2. Kh7
  3. Ra7+
  4. Kg8
  5. Kf6
  6. Kh8
  7. Ra8+
  8. Kh7
  9. Rb8
  10. Kh6
  11. Rh8#

Practice Position Solutions

Rook and King Checkmate — Practice 1

White to move. Find checkmate in one.

Solution: Rh1#

The white king on f7 already covers g7 and g8, so the black king can't step sideways. Rh1 checks along the h-file, and since g7/g8 are covered by the white king, there is no escape.

Rook and King Checkmate — Practice 2

Before checking, improve your king. Find the safe king move that helps the rook.

Solution: Kf5

The rook alone cannot mate. Kf5 brings the king closer so it can take away escape squares later.

Rook and King Checkmate — Practice 3

Now use the rook to cut the king off from one more rank.

Solution: Ra7+

Ra7+ is a useful rook check because it also builds a wall. The black king is pushed closer to the edge.

Rook and King Checkmate — Practice 4

Finish the rook-and-king technique from here. Find White’s full line to mate.

Solution: Ra8+ Kh7 Rb8 Kh6 Rh8#

The rook first gives check from the edge, then shifts to the next wall, and finally mates once the white king covers the last escape squares.

Pawn Promotion

Teacher/parent key for Worksheet: Pawn Promotion.

Worksheet Answers

  1. Prompt: List the four pieces a pawn may promote to.

    Queen, rook, bishop, or knight.

  2. Prompt: Why is “always make a queen” a good habit most of the time but not a perfect rule?

    A queen is usually strongest, but sometimes another piece is needed to avoid stalemate or to give a special kind of check.

  3. Prompt: Solve the promotion positions and mark the underpromotions with a star.

    The second and third practice positions are underpromotions; the others use the usual queen promotion.

Model Line

  1. g8=Q+
  2. Kb7
  3. Qxa2
  4. Kc6
  5. Kf6
  6. Kb5

Practice Position Solutions

Pawn Promotion — Practice 1

Your pawn reached the last rank. Promote to the strongest piece and finish the game.

Solution: a8=Q#

Most of the time a queen is best. Here a8=Q# is immediate mate because the king and queen cover every escape square.

Pawn Promotion — Practice 2

A queen here would freeze the game by stalemate. Choose the promotion that keeps winning chances.

Solution: b8=N

Promoting to a knight keeps the game going. A queen or rook would leave Black with no legal move and no check: stalemate. White's spare rook means either underpromotion keeps enough material to win.

Pawn Promotion — Practice 3

This time a queen would also stalemate. Pick a different promotion that still keeps control.

Solution: b8=R

b8=R keeps one legal move for Black, so the game continues. Underpromotion is rare, but you must know it exists.

Pawn Promotion — Practice 4

Both sides have a pawn close to promotion. Promote first so your new piece can handle the race.

Solution: g8=Q+

Promoting first gives White a brand-new queen before Black’s pawn can become dangerous.

Passed Pawns

Teacher/parent key for Worksheet: Passed Pawns.

Worksheet Answers

  1. Prompt: Write the definition of a passed pawn using the words “same file” and “next file.”

    A passed pawn has no enemy pawn in front of it on its own file or the files next to it.

  2. Prompt: Why can an outside passed pawn be extra annoying for the defender?

    It can drag the enemy king far away from the rest of the pawns and pieces.

  3. Prompt: Solve the practice positions and label each new passed pawn as center, side, or outside.

    Practice 1 and 2 create center passed pawns, Practice 3 shows Black doing the same, and Practice 4 makes an outside passed pawn.

Model Line

  1. d6
  2. Kg8
  3. d7
  4. Kf7
  5. d8=Q
  6. Kg6

Practice Position Solutions

Passed Pawns — Practice 1

Push the pawn so it becomes a real passed pawn.

Solution: d5

After d5, no black pawn stands in front of it on the c-, d-, or e-files. That makes it a passed pawn.

Passed Pawns — Practice 2

Create a passed pawn by capturing the blocker.

Solution: cxd5

The capture lands on d5 and removes the only pawn that was stopping White from having a passed pawn.

Passed Pawns — Practice 3

Black to move: push the pawn so it becomes passed.

Solution: e4

Black’s pawn on e4 has no white pawns ahead of it on the d-, e-, or f-files, so it becomes a passed pawn too.

Passed Pawns — Practice 4

Use a capture to make an outside passed pawn.

Solution: axb5

After axb5, White owns a passed pawn far from the kingside. Outside passed pawns can pull the enemy king away.

Rule of the Square

Teacher/parent key for Worksheet: Rule of the Square.

Worksheet Answers

  1. Prompt: Explain what the square starts from and how wide it is.

    The square starts on the pawn’s square and reaches to the promotion rank with the same width as height.

  2. Prompt: Why is the rule of the square useful even before you calculate every move?

    It gives a fast yes-or-no answer before you calculate every move in detail.

  3. Prompt: Play out the three races and write whether the king catches the pawn or the pawn escapes.

    Practice 1: king catches. Practice 2: pawn escapes. Practice 3: king catches.

Model Line

  1. Kd4
  2. c3
  3. Kxc3
  4. Kg7
  5. Kd4
  6. Kg6

Practice Position Solutions

Rule of the Square — Practice 1

White to move. Play out the race and show that the king is inside the square.

Solution: Kd4 c3 Kxc3

The king steps into the square in time and catches the pawn on c3.

Rule of the Square — Practice 2

White to move. Play the race and prove that the king is outside the square.

Solution: Kf2 c1=Q

White is too far away. The pawn reaches the last rank before the king can catch it.

Rule of the Square — Practice 3

Rook pawns have a funny-shaped race too. Play it out and show the king still catches this one.

Solution: Kc3 a4 Kb4 a3 Kxa3

Even against the rook pawn, White stays close enough to enter the square and capture it on a3.

Basic Opposition

Teacher/parent key for Worksheet: Basic Opposition.

Worksheet Answers

  1. Prompt: Draw two kings in direct opposition and label the square between them.

    The kings should face each other with exactly one square between them.

  2. Prompt: Why can the side to move be the side with the problem in king endings?

    Because the side to move may have to step aside first and allow the other king to enter.

  3. Prompt: Solve the practice positions and write where the kings stand at the end of each line.

    Each practice line ends with direct opposition on the e-file.

Model Line

  1. Kd3
  2. Ke5
  3. Ke3
  4. Kd5
  5. Kd3
  6. Ke5
  7. Ke3

Practice Position Solutions

Basic Opposition — Practice 1

Take opposition on the same file and keep it after Black moves.

Solution: Kd3 Ke5 Ke3

White steps in front, Black slides, and White slides too. The kings finish with one square between them on the e-file.

Basic Opposition — Practice 2

Use the same idea when the kings are more sideways than straight on.

Solution: Kd2 Ke4 Ke2

White walks into the right line, Black replies, and White keeps the direct opposition on the e-file.

Basic Opposition — Practice 3

Play three king moves and finish with direct opposition again.

Solution: Kd4 Ke6 Ke4

White moves into line with the black king and ends with one square between the kings on the e-file.

Trade When Ahead

Teacher/parent key for Worksheet: Trade When Ahead.

Worksheet Answers

  1. Prompt: Finish this sentence: “When I am ahead, trading pieces helps because ...”

    ...there are fewer enemy pieces left to attack me, so my winning edge is easier to use.

  2. Prompt: Name one time when trading is a bad idea even if you are ahead.

    Trading can be bad if it causes stalemate or if it turns a winning position into a drawn pawn ending.

  3. Prompt: Solve the four trade positions and write which enemy piece gets removed each time.

    Practice 1 trades a pair of rooks, Practice 2 a pair of knights, Practice 3 a pair of queens, and Practice 4 a pair of bishops — in every case the mover starts ahead and stays ahead after the trade.

Model Line

  1. Rxe8+
  2. Rxe8
  3. Kf2
  4. Kf8
  5. Kf3
  6. h6

Practice Position Solutions

Trade When Ahead — Practice 1

White is already ahead by a bishop. Offer a rook trade to simplify without giving anything back.

Solution: Rxe8+ Rxe8

White's rook captures Black's rook with check, and Black is forced to recapture with the other rook. A whole pair of rooks leaves the board, but White's extra bishop — and the winning edge it gives — stays exactly the same.

Trade When Ahead — Practice 2

White is ahead. Trade off the knights to reduce Black's counterplay.

Solution: Nxc6 dxc6

White's knight captures Black's knight, and Black recaptures with a pawn. Both knights disappear, but White keeps the same material edge with fewer pieces on the board to create trouble.

Trade When Ahead — Practice 3

Black is ahead by the exchange. Trade the queens to head into a simpler, safer ending.

Solution: Qxd4 Bxd4

Black's queen captures White's queen, and White recaptures with the bishop. With the queens off the board there are far fewer tactics for White to try, and Black's rook-for-bishop edge remains.

Trade When Ahead — Practice 4

White is ahead by a whole rook. Trade off the bishops so Black has nothing left to fight with.

Solution: Bxf5 gxf5

White's bishop captures Black's bishop, and Black recaptures with a pawn. Once the only minor pieces are gone, White's extra rook is enough to win easily, with almost no risk left for Black to create.