user14678: This is a big-list question regarding chess themes (mostly tactical). There are some puzzles that illustrate important aspects of a tactic (esp. useful in a chess coaching setting). For example, the following puzzle speaks volumes about pin.
[Title "Adapted from Schatz vs. Giegold, Hof (1928)"]
[FEN "7k/pb2q3/1p3p2/2prp1p1/6P1/1P1R4/PQ3PP1/1B5K b - - 0 1"]

1...Qh7+ 2.Rh3 Rd1+ 3.Kh2 Rh1+ 4.Kg3 
    ( 4.Kxh1 Qxh3+ 5.Kg1 Qxg2# )
4...Qh4+ 5.Rxh4+ gxh4#

Credit: Adapted from Martin Weteschnik, Understanding Chess Tactics.
In particular, the puzzle illustrates creating a pin, and that absolutely pinned piece can move and bring about surprises.
Include only one puzzle per answer. The value of an answer should be decided by the following:

How good the puzzle illustrates various points of the theme (mention the theme and the specific points of theme illustrated by the puzzle).
How beautiful and/or surprising the puzzle is.

To be clear, the difficulty of a puzzle is a demerit if it becomes a hurdle for the puzzle to illustrate the theme to most of the audience.
Also, include the details of the game or the composition.

user14678: Theme: Pin
Illustrated points:

Creating pin - Method 2: Attacking piece and the piece to be pinned are in one line, lure the third piece to the same line.
Even absolutely pinned piece can move (though its mobility is restricted to the pinning line).

Puzzle:
[Title "Adapted from Schatz vs. Giegold, Hof (1928)"]  
[FEN "7k/pb2q3/1p3p2/2prp1p1/6P1/1P1R4/PQ3PP1/1B5K b - - 0 1"]

1...Qh7+ 2.Rh3 Rd1+ 3.Kh2 Rh1+ 4.Kg3 
    ( 4.Kxh1 Qxh3+ 5.Kg1 Qxg2# )
4...Qh4+ 5.Rxh4+ gxh4#

Source: Adapted from Martin Weteschnik, Understanding Chess Tactics.

14678: <p>This is a big-list question regarding chess themes (mostly tactical). There are some puzzles that illustrate important aspects of a tactic (esp. useful in a chess coaching setting). For example, the following puzzle speaks volumes about pin.</p>
<pre><code>[Title &quot;Adapted from Schatz vs. Giegold, Hof (1928)&quot;]
[FEN &quot;7k/pb2q3/1p3p2/2prp1p1/6P1/1P1R4/PQ3PP1/1B5K b - - 0 1&quot;]

1...Qh7+ 2.Rh3 Rd1+ 3.Kh2 Rh1+ 4.Kg3 
    ( 4.Kxh1 Qxh3+ 5.Kg1 Qxg2# )
4...Qh4+ 5.Rxh4+ gxh4#
</code></pre>
<p>Credit: Adapted from Martin Weteschnik, <a href="https://www.pathtochessmastery.com/2012/06/book-completed-understanding-chess.html" rel="nofollow noreferrer">Understanding Chess Tactics</a>.</p>
<p>In particular, the puzzle illustrates creating a pin, and that absolutely pinned piece can move and bring about surprises.</p>
<p>Include only <strong>one puzzle per answer</strong>. The value of an answer should be decided by the following:</p>
<ol>
<li>How good the puzzle illustrates various points of the theme (mention the theme and the specific points of theme illustrated by the puzzle).</li>
<li>How beautiful and/or surprising the puzzle is.</li>
</ol>
<p>To be clear, the difficulty of a puzzle is a demerit if it becomes a hurdle for the puzzle to illustrate the theme to most of the audience.</p>
<p>Also, include the details of the game or the composition.</p>
 14678: <p>Theme: Pin<br />
Illustrated points:</p>
<ol>
<li>Creating pin - Method 2: Attacking piece and the piece to be pinned are in one line, lure the third piece to the same line.</li>
<li>Even absolutely pinned piece can move (though its mobility is restricted to the pinning line).</li>
</ol>
<p>Puzzle:</p>
<pre><code>[Title &quot;Adapted from Schatz vs. Giegold, Hof (1928)&quot;]  
[FEN &quot;7k/pb2q3/1p3p2/2prp1p1/6P1/1P1R4/PQ3PP1/1B5K b - - 0 1&quot;]

1...Qh7+ 2.Rh3 Rd1+ 3.Kh2 Rh1+ 4.Kg3 
    ( 4.Kxh1 Qxh3+ 5.Kg1 Qxg2# )
4...Qh4+ 5.Rxh4+ gxh4#
</code></pre>
<p>Source: Adapted from Martin Weteschnik, <a href="https://www.pathtochessmastery.com/2012/06/book-completed-understanding-chess.html" rel="nofollow noreferrer">Understanding Chess Tactics</a>.</p>
