user27116: I am a beginner. Recently I have looked at the computer-generated analysis of one of my games and I found a surprising recommendation. Why is it best to sacrifice my Queen in this situation, as the screenshot shows?
[FEN ""]
[StartPly "10"]

1. e4 e5 2. Qf3 c6 3. Bxc4 Nf6 4. d3 d6 5. Bg5 Bg4




user15238: The other answers already explain what's going on, but there's standard terminology for it:
This is not actually a sacrifice, merely a queen trade, because the knight is pinned against the black queen.

user7297: As @Ibrahim explains, you'll win the queen back, but after that White can even take the pawn on f7:
[FEN ""]
[StartPly "10"]

1. e4 e5 2. Qf3 c6 3. Bxc4 Nf6 4. d3 d6 5. Bg5 Bg4 6. Qxg4 Nxg4 7. Bxd8 Kxd8 8. Bxf7

and White is a pawn up.

user27117: It's basically a trade. After you take the bishop, if the opponent takes your queen with the knight, then your bishop is no longer blocked by the knight and you can take their queen too. The advantage here is that after the trade, the opponent's king will have to take your bishop, and thus can no longer castle.

27116: <p>I am a beginner. Recently I have looked at the computer-generated analysis of one of my games and I found a surprising recommendation. Why is it best to sacrifice my Queen in this situation, as the screenshot shows?</p>
<pre><code>[FEN &quot;&quot;]
[StartPly &quot;10&quot;]

1. e4 e5 2. Qf3 c6 3. Bxc4 Nf6 4. d3 d6 5. Bg5 Bg4
</code></pre>
<hr />
<p><a href="https://i.stack.imgur.com/AEvfb.png" rel="noreferrer"><img src="https://i.stack.imgur.com/AEvfbl.png" alt="enter image description here" /></a></p>
 15238: <p>The other answers already explain what's going on, but there's standard terminology for it:</p>
<p><em>This is not actually a sacrifice, merely a queen <strong>trade</strong>, because <strong>the knight is <a href="https://en.wikipedia.org/wiki/Pin_(chess)" rel="noreferrer">pinned</a></strong> against the black queen.</em></p>
 7297: <p>As <a href="https://chess.stackexchange.com/a/34582/7297">@Ibrahim explains</a>, you'll win the queen back, but after that White can even take the pawn on f7:</p>
<pre><code>[FEN &quot;&quot;]
[StartPly &quot;10&quot;]

1. e4 e5 2. Qf3 c6 3. Bxc4 Nf6 4. d3 d6 5. Bg5 Bg4 6. Qxg4 Nxg4 7. Bxd8 Kxd8 8. Bxf7
</code></pre>
<p>and White is a pawn up.</p>
 27117: <p>It's basically a trade. After you take the bishop, if the opponent takes your queen with the knight, then your bishop is no longer blocked by the knight and you can take their queen too. The advantage here is that after the trade, the opponent's king will have to take your bishop, and thus can no longer castle.</p>
