user24850: Ive been learning the theory for this opening but cant find anything if black chooses this line.

user924: You probably mean 4...Nxb4.
White will play 5.c3, and there is probably nothing better than 5...Nc6; so it boils down to being the same as 4...Bxb4 5.c3 Bc5.
[FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Nxb4 5.c3 Nc6


24850: <p>Ive been learning the theory for this opening but cant find anything if black chooses this line.</p>
 924: <p>You probably mean 4...Nxb4.</p>
<p>White will play 5.c3, and there is probably nothing better than 5...Nc6; so it boils down to being the same as 4...Bxb4 5.c3 <strong>Bc5</strong>.</p>
<pre><code>[FEN &quot;&quot;]

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Nxb4 5.c3 Nc6
</code></pre>
