user1435: What is the minimum number of moves, counting both sides, in which a checkmate can be made?

user86: The precise answer to your question is four half-moves. The only checkmate possible in two moves is by Black - 1.f3 e5 2.g4 Qh4# (This mate is known as Fool's Mate). Slight variations may occur (in White's move order or in the distance Black's e-pawn or White's f-pawn is advanced):
1.g4 e5 2.f3 Qh4#
1.f3 e6 2.g4 Qh4#
1.g4 e6 2.f3 Qh4#
1.g4 e5 2.f4 Qh4#
1.f4 e5 2.g4 Qh4#
1.g4 e6 2.f4 Qh4#
1.f4 e6 2.g4 Qh4#

If White is to mate, a minimum of five half-moves (three moves) is required, for example 1.e4 f6 2.d4 g5 3.Qh5# (with similar variations possible).

1435: <p>What is the minimum number of moves, counting both sides, in which a checkmate can be made?</p>
 86: <p>The precise answer to your question is <strong>four half-moves</strong>. The only checkmate possible in two moves is by Black - <code>1.f3 e5 2.g4 Qh4#</code> (This mate is known as <a href="http://en.wikipedia.org/wiki/Fool%27s_mate" rel="noreferrer">Fool's Mate</a>). Slight variations may occur (in White's move order or in the distance Black's e-pawn or White's f-pawn is advanced):</p>

<pre><code>1.g4 e5 2.f3 Qh4#
1.f3 e6 2.g4 Qh4#
1.g4 e6 2.f3 Qh4#
1.g4 e5 2.f4 Qh4#
1.f4 e5 2.g4 Qh4#
1.g4 e6 2.f4 Qh4#
1.f4 e6 2.g4 Qh4#
</code></pre>

<p>If White is to mate, a minimum of five half-moves (three moves) is required, for example <code>1.e4 f6 2.d4 g5 3.Qh5#</code> (with similar variations possible).</p>
