Reflex Chess

The corner mate

A knight is the only piece that can check a king without standing next to it. Against a king in the corner that is nearly enough on its own.

The pattern

abcdefgh12345678
The pattern, finished. The black king on h8 is in check from the knight on f7, which the queen on g6 defends. It has three squares to try and none of them work: g7, g8 and h7 are covered by the queen on g6.

The king is in a corner, so it has three squares. The knight checks it from two squares away, which no other piece can do without coming into reach of the king. The check cannot be blocked, because a knight's check never can be, and it cannot be answered by taking the knight.

What the knight cannot do is cover any of the three squares, and this is the part worth knowing: a knight checking a king in the corner never covers a single square next to it. Look at f7 against h8 -- the knight attacks h6, g5, e5, d6 and d8, and not one of g8, g7 or h7. All three have to be taken by something else, which in practice means a rook or a queen on the neighbouring file or rank, plus whatever the defender has left standing next to its own king.

It is the reverse of the Arabian mate in the same corner. There the rook gives the check and the knight defends it; here the knight gives the check and the rook covers what is left.

What is always true

Each line below was tested against all 7 positions in this course that show the pattern, using the same rules engine the trainer runs on. The build stops if any of them is ever false, so the count beside each one is the real count.

How to spot it

4 positions to solve

Real games, easiest first. The amber squares are the move your opponent has just played, not the answer. Work it out before you open the solution; the second diagram inside each answer is the finished mate with the trapped king outlined.

The course carries 31 positions tagged with this name; in seven of them the king is genuinely in a corner with a knight giving the check, and those seven are the only ones used here.

Position 1

abcdefgh12345678

White to move. Force the mate.

Show the answer

31...Kxg7 32.Qg6+ Kh8 33.Nf7#

abcdefgh12345678

The black king on h8 is in check from the knight on f7, which the queen on g6 defends. It has three squares to try and none of them work: g7, g8 and h7 are covered by the queen on g6.

The position comes from the middlegame of a real game, rated 961 in the Lichess pool and scored there as mate in two. The amber squares on the first diagram are the move your opponent had just played.

Position 2

abcdefgh12345678

White to move. Force the mate.

Show the answer

28...Kg7 29.Rxf7+ Rxf7 30.Qg6+ Kh8 31.Nxf7#

abcdefgh12345678

The black king on h8 is in check from the knight on f7, which the queen on g6 defends. It has three squares to try and none of them work: g7, g8 and h7 are covered by the queen on g6.

The position comes from an endgame of a real game, rated 1428 in the Lichess pool and scored there as mate in three. The amber squares on the first diagram are the move your opponent had just played.

Position 3

abcdefgh12345678

White to move. Force the mate.

Show the answer

26...gxf4 27.Nh6+ Kh8 28.Nf7#

abcdefgh12345678

The black king on h8 is in check from the knight on f7. It has three squares to try and none of them work: g7 and g8 are covered by the queen on g3; h7 is blocked by its own pawn.

The position comes from the middlegame of a real game, rated 1715 in the Lichess pool and scored there as mate in two. The amber squares on the first diagram are the move your opponent had just played.

Position 4

abcdefgh12345678

White to move. Force the mate.

Show the answer

26...Nf6 27.Ne5+ Nxg4 28.Rg5+ Kh8 29.Nxf7#

abcdefgh12345678

The black king on h8 is in check from the knight on f7. It has three squares to try and none of them work: g7 and g8 are covered by the rook on g5; h7 is blocked by its own pawn.

The position comes from the middlegame of a real game, rated 2053 in the Lichess pool and scored there as mate in three. The amber squares on the first diagram are the move your opponent had just played.

Drill the named mates until you see them 120 positions on the named mating patterns, in five graded levels, in the free Reflex Chess trainer. No account needed to start. Practise named mates

Easy to confuse with

These are the patterns Corner Mate gets mistaken for. The difference is usually one piece or one square.

Questions people ask

What is the corner mate in chess?

A checkmate against a king in the corner, delivered by a knight, with a rook or queen covering the squares the knight does not reach.

How is the corner mate different from the Arabian mate?

The roles are swapped. In the Arabian mate the rook gives the check from next to the king and the knight defends it. In the corner mate the knight gives the check and the rook or queen covers the escape squares.

All the named mates

One page each, or the whole set as a single motif in the course. The rest of the tactics library is at every motif in the course.