user1315: The Ruy Lopez is one of the most difficult lines for me to play against.  I just can't hold my position when I play as black. If I move 3... Nd4, I always get a draw at best, and usually take a loss. How can I improve my chances of winning in this situation?
EDIT : 
After I looked up the answers which were given to me, I found one solid win for black with the Cordel Defence that I found in Shredder Computer Chess if you insert this FEN to it.
[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 Bb6 5. d4 exd4 6. cxd4 Nce7 7. d5 Nf6 8. Nc3 O-O

Can someone show me, at which point does black take the initiative from white??
Thanks, 
Ahmad

user1315: Thanks for all of you who have been give me the answer, and I realized that Classical Defence as Ruy Lopez variation fits me than the others variation. 
From the latest FEN that I have been edited (and based from @Tom Au answer), normally White player will choose to castle his king, so it will give Black opportunity to neutralize centre with 9. O-O d6.
After I analyzed, 7. d5 is just bad idea from White player that give advantages to Black. It means, Black knight in 7. ... Nf6 is in the right place at the right time.

user17: Frankly, I don't like my chances of winning with Ruy Lopez as Black. When faced with 1. e4, I "never" reply with 1... e5 (except as a "surprise" - then I play 2... Nf6, the Petrov Defense, but mainly to draw, rather than to win.)
I prefer 1... c5 (Sicilian Defense) or 1... e6 (French Defense). These are "double-edged" openings that allow both Black and White to win OR lose.
I like your variation better than most. After your 8... O-O, White will play 9. O-O, and you can play 9... Ng6. That leads to a position somewhat like my French defenses (with White's center pawns on "reversed" colors). It's a tough, but by no means unplayable game that gives White fewer attacking chances than a conventional Ruy.
I've lost a few games with the Ruy Lopez playing White. But that was basically due to my ignorance of the opening more than anything else.

user1382: A "chance to win" with Black against the Ruy Lopez isn't necessary dependent on variation. Yes, there are aggressive lines, the most notable being the Archangel Variation, but having a better understanding of the opening line that you play will result in improved results. I would research other lines by using the Shredder Opening Database and see what other people are playing. Then, I would go online and play a few games in each variation to get a feel of the resulting middlegame positions and see which one is the best fit for me.

user279: The Ruy Lopez is probably one of the most analyzed openings in chess. You can find plenty of resources on the Internet. (Wikipedia's article on the Ruy Lopez is a good point to start).
I would recommend that you not go searching for "winning lines". You first need to understand the principles that lie behind each move of this opening. Once you have that understanding it is easier to examine variations and choose the one that best suits your needs.
For example, if you are an aggressive player and your chess level is average, you might wish to consider the Open Defense and the Marshall Attack.

1315: <p>The Ruy Lopez is one of the most difficult lines for me to play against.  I just can't hold my position when I play as black. If I move <code>3... Nd4</code>, I always get a draw at best, and usually take a loss. How can I improve my chances of winning in this situation?</p>

<p><strong>EDIT :</strong> <br>
After I looked up the answers which were given to me, I found one solid win for black with the <a href="https://en.wikipedia.org/wiki/Ruy_Lopez#Classical_Defence" rel="nofollow">Cordel Defence</a> that I found in Shredder Computer Chess if you insert this FEN to <a href="http://www.shredderchess.com/online-chess/online-databases/opening-database.html" rel="nofollow">it</a>.</p>

<pre><code>[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 Bb6 5. d4 exd4 6. cxd4 Nce7 7. d5 Nf6 8. Nc3 O-O
</code></pre>

<p>Can someone show me, at which point does black take the initiative from white??</p>

<p>Thanks, <br>
Ahmad</p>
 1315: <p>Thanks for all of you who have been give me the answer, and I realized that <strong>Classical Defence</strong> as <strong>Ruy Lopez</strong> variation fits me than the others variation. </p>

<p>From the latest FEN that I have been edited (and based from @<a href="https://chess.stackexchange.com/questions/2435/how-do-i-increase-my-chances-to-win-as-black-in-the-ruy-lopez/2446#2446"><strong>Tom Au</strong></a> answer), normally White player will choose to castle his king, so it will give Black opportunity to neutralize centre with <code>9. O-O d6</code>.</p>

<p>After I analyzed, <code>7. d5</code> is just bad idea from White player that give advantages to Black. It means, Black knight in <code>7. ... Nf6</code> is in the right place at the right time.</p>
 17: <p>Frankly, I don't like my chances of winning with Ruy Lopez as Black. When faced with <code>1. e4</code>, I "never" reply with <code>1... e5</code> (except as a "surprise" - then I play <code>2... Nf6</code>, the Petrov Defense, but mainly to draw, rather than to win.)</p>

<p>I prefer <code>1... c5</code> (Sicilian Defense) or <code>1... e6</code> (French Defense). These are "double-edged" openings that allow both Black and White to win OR lose.</p>

<p>I like your variation better than most. After your <code>8... O-O</code>, White will play <code>9. O-O</code>, and you can play <code>9... Ng6</code>. That leads to a position somewhat like my French defenses (with White's center pawns on "reversed" colors). It's a tough, but by no means unplayable game that gives White fewer attacking chances than a conventional Ruy.</p>

<p>I've lost a few games with the Ruy Lopez playing White. But that was basically due to my ignorance of the opening more than anything else.</p>
 1382: <p>A "chance to win" with Black against the Ruy Lopez isn't necessary dependent on variation. Yes, there are aggressive lines, the most notable being the <a href="http://www.chesspublishing.com/content/1/oct04.htm">Archangel Variation</a>, but having a better understanding of the opening line that you play will result in improved results. I would research other lines by using the <a href="http://www.shredderchess.com/online-chess/online-databases/opening-database.html">Shredder Opening Database</a> and see what other people are playing. Then, I would go online and play a few games in each variation to get a feel of the resulting middlegame positions and see which one is the best fit for me.</p>
 279: <p>The Ruy Lopez is probably one of the most analyzed openings in chess. You can find plenty of resources on the Internet. (<a href="https://en.wikipedia.org/wiki/Ruy_Lopez">Wikipedia's article on the Ruy Lopez</a> is a good point to start).</p>

<p>I would recommend that you not go searching for "winning lines". You first need to understand the principles that lie behind each move of this opening. Once you have that understanding it is easier to examine variations and choose the one that best suits your needs.</p>

<p>For example, if you are an aggressive player and your chess level is average, you might wish to consider the <a href="https://en.wikipedia.org/wiki/Ruy_Lopez#Open_Defence">Open Defense</a> and the <a href="https://en.wikipedia.org/wiki/Ruy_Lopez#Marshall_Attack">Marshall Attack</a>.</p>
