user827: [fen ""]

1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4 Nf6 5. Ng5 d5 6. exd5 Nxd5 7. Nxf7 Kxf7 8. Qf3+ Ke6 

Now the usual move in the Fried Liver Attack is 9. Nc3 attacking the knight on d5, but the d-pawn heads this off. Is the Fried Liver Attack still viable in the Scotch Gambit/Two Knights Defense?

user1485: It's better to castle on move 7 and sacrifice the knight next move. Black will have a hard time defending against this.
The variation with 5.Ng5 is called the Perreux Variation and is extensively analysed at the following site: 
The Perreux Variation of the Two Knights Defense
A critical line begins with 6...Qe7+!
   [fen ""]

   1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.Ng5 d5 6.exd5 Qe7+!

White might have to respond 7.Kf1, see the analyses given in the link.

user70: Given the moves in your post, the position favors White.  I think most White players would enjoy the seeing the Black King out there, suffering a pin, sitting on an open file, and flapping in the breeze on move 8 with Queens on the board.
Here's what Stockfish thinks after a reasonably long think:


[fen ""]
1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Nf6 5.Ng5 d5 6.exd5 Nxd5 7.Nxf7 Kxf7 8.Qf3+ Ke6 
 9.O-O Ne5 10.Re1 c6 11.Bf4 Bd6 12.Qg3 Qf6 13.Nd2 Re8 14.Nf3 Kf7 15.Nxe5+ Kg8 16.Nd3 Rxe1+ 17.Rxe1 Bf8 18.Be5 Qh6 19.Bxd4 Be6 20.Bb3 a5 21.a4 Bf7 22.h3 Rd8 23.Ne5


...with a small advantage for White.  I see both players having a good game here.  However, I suspect Black is walking a tightrope.  That is, to maintain parity, Black must play much better than White.

827: <pre><code>[fen ""]

1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4 Nf6 5. Ng5 d5 6. exd5 Nxd5 7. Nxf7 Kxf7 8. Qf3+ Ke6 
</code></pre>

<p>Now the usual move in the Fried Liver Attack is <code>9. Nc3</code> attacking the knight on <code>d5</code>, but the <code>d</code>-pawn heads this off. Is the Fried Liver Attack still viable in the Scotch Gambit/Two Knights Defense?</p>
 1485: <p>It's better to castle on move 7 and sacrifice the knight next move. Black will have a hard time defending against this.</p>

<p>The variation with <code>5.Ng5</code> is called the Perreux Variation and is extensively analysed at the following site: 
<a href="http://www.rci.rutgers.edu/~goeller/urusov/perreux/" rel="nofollow">The Perreux Variation of the Two Knights Defense</a></p>

<p>A critical line begins with <code>6...Qe7+!</code></p>

<pre><code>   [fen ""]

   1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.Ng5 d5 6.exd5 Qe7+!
</code></pre>

<p>White might have to respond <code>7.Kf1</code>, see the analyses given in the link.</p>
 70: <p>Given the moves in your post, the position favors White.  I think most White players would enjoy the seeing the Black King out there, suffering a pin, sitting on an open file, and flapping in the breeze on move 8 with Queens on the board.</p>

<p>Here's what Stockfish thinks after a reasonably long think:</p>

<pre>
<code>
[fen ""]
1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 Nf6 5.Ng5 d5 6.exd5 Nxd5 7.Nxf7 Kxf7 8.Qf3+ Ke6 
 9.O-O Ne5 10.Re1 c6 11.Bf4 Bd6 12.Qg3 Qf6 13.Nd2 Re8 14.Nf3 Kf7 15.Nxe5+ Kg8 16.Nd3 Rxe1+ 17.Rxe1 Bf8 18.Be5 Qh6 19.Bxd4 Be6 20.Bb3 a5 21.a4 Bf7 22.h3 Rd8 23.Ne5
</code>
</pre>

<p>...with a small advantage for White.  I see both players having a good game here.  However, I suspect Black is walking a tightrope.  That is, to maintain parity, Black must play <em>much</em> better than White.</p>
