user2785: [fen "5k2/8/1R6/5r2/P7/1P4P1/6KP/5n2 b - - 0 40"]

With black to move, remarkably it's mate in 2 (at first glance, it looks like black may struggle to even draw).  It occurred in a recent LiChess game of mine.  It looks like the kind of position that might occur in a composed puzzle because it contains the precise material required to checkmate.
Question: Does this knight and rook mating pattern have a name, or has it occurred before?
When there's a mating pattern involving so little material (just the rook and knight, no king), I feel it might be worthwhile studying it in its own right.  The knight and rook could be on multiple other squares and still achieve essentially the same mate.

user10380: That is a nice problem, with rook and knight mating a king at the edge, with one square blocked. Here's a helpmate problem which shows more examples of that phenomenon:
[Title "Forsberg, Revista Romana de Sah, 1935. h#2. b) bRa6 c) bBa6 d) bNa6 e) bPa6"]
[StartFlipped "0"]
[fen "8/8/q7/8/1R4K1/k2N4/8/8 b KQkq - 0 1"]

1... Qf6 2. Nc5 Qb2 3. Ra4#

My analysis is based on that by John Nunn, Solving in Style, prob. 133. White's king is too far away to participate in the mating-net (though it is accurately placed to avoid dual solutions). So White must mate with rook and knight alone. Rook and knight can mate, but only if bK is in a corner. With only 2 Black moves, this corner must be a1, but this entails wNc3, which the knight can't reach in two moves. Therefore Black must block one square in bK's field, and this is where the unit on a6 comes in. The 5 choices of unit lead to 5 different mating nets.

user15543: I believe that that is called “Anatasia Mate,” based on Wikipeda's testimony.

In Anastasia's mate, a knight and rook team up to trap the opposing king between the side of the board on one side and a friendly piece on the other. Often, the queen is first sacrificed along the a-file or h-file to achieve the position. This checkmate gets its name from the novel Anastasia und das Schachspiel by Johann Jakob Wilhelm Heinse.

It gives this position as an example of Anatasia mate.
[FEN "8/4N1pk/8/7R/8/8/8/8 w - - 0 1"]

Now compare it to the checkmate from your game.
[FEN "5k2/8/1R6/7r/P7/1P2n1PK/7P/8 w - - 0 1"]

Even though the White king has an extra pawn by it, I believe it to be similar enough to call it an Anatasia mate.

2785: <pre><code>[fen "5k2/8/1R6/5r2/P7/1P4P1/6KP/5n2 b - - 0 40"]
</code></pre>

<p>With black to move, remarkably it's mate in 2 (at first glance, it looks like black may struggle to even draw).  It occurred in <a href="https://lichess.org/zohTb2tR" rel="noreferrer">a recent LiChess game of mine</a>.  It looks like the kind of position that might occur in a composed puzzle because it contains the precise material required to checkmate.</p>

<p><strong>Question</strong>: Does this knight and rook mating pattern have a name, or has it occurred before?</p>

<p>When there's a mating pattern involving so little material (just the rook and knight, no king), I feel it might be worthwhile studying it in its own right.  The knight and rook could be on multiple other squares and still achieve essentially the same mate.</p>
 10380: <p>That is a nice problem, with rook and knight mating a king at the edge, with one square blocked. Here's a helpmate problem which shows more examples of that phenomenon:</p>

<pre><code>[Title "Forsberg, Revista Romana de Sah, 1935. h#2. b) bRa6 c) bBa6 d) bNa6 e) bPa6"]
[StartFlipped "0"]
[fen "8/8/q7/8/1R4K1/k2N4/8/8 b KQkq - 0 1"]

1... Qf6 2. Nc5 Qb2 3. Ra4#
</code></pre>

<p>My analysis is based on that by John Nunn, <em>Solving in Style</em>, prob. 133. White's king is too far away to participate in the mating-net (though it is accurately placed to avoid dual solutions). So White must mate with rook and knight alone. Rook and knight can mate, but only if bK is in a corner. With only 2 Black moves, this corner must be a1, but this entails wNc3, which the knight can't reach in two moves. Therefore Black must block one square in bK's field, and this is where the unit on a6 comes in. The 5 choices of unit lead to 5 different mating nets.</p>
 15543: <p>I believe that that is called “Anatasia Mate,” based on <a href="https://en.m.wikipedia.org/wiki/Checkmate_pattern" rel="nofollow noreferrer">Wikipeda's</a> testimony.</p>
<blockquote>
<p>In Anastasia's mate, a knight and rook team up to trap the opposing king between the side of the board on one side and a friendly piece on the other. Often, the queen is first sacrificed along the a-file or h-file to achieve the position. This checkmate gets its name from the novel Anastasia und das Schachspiel by Johann Jakob Wilhelm Heinse.</p>
</blockquote>
<p>It gives this position as an example of Anatasia mate.</p>
<pre><code>[FEN &quot;8/4N1pk/8/7R/8/8/8/8 w - - 0 1&quot;]
</code></pre>
<p>Now compare it to the checkmate from your game.</p>
<pre><code>[FEN &quot;5k2/8/1R6/7r/P7/1P2n1PK/7P/8 w - - 0 1&quot;]
</code></pre>
<p>Even though the White king has an extra pawn by it, I believe it to be similar enough to call it an Anatasia mate.</p>
