user47: I always thought it was interesting that chess players had openings named after them.  The game of chess has only been popular and organized for about 150 years, yet all the most popular openings and most of their sub-variations have already been named, many after players from the 19th or early 20th centuries.  In five hundred years, will all these basic openings still be named after Morphy, Steinitz, Capablanca, and Lasker?  But I digress.
Which player has had the most openings or opening variations named after him?  My guesses would be Botvinnik or Aljechin (Alekhine).

user103: Using Wikipedia as a guide, I can see that Frank Marshall, Carl Schlecter and Akiba Rubinstein have about 5 opening variations named after them.

user12: Off the top of my head, there are a few players with multiple openings named after them:
Tarrasch

Tarrasch Variation against the French Defense
Tarrasch Opening against d4 (with ...d5 and ...c5)
the Open Variation in the Ruy Lopez is technically the Tarrasch

Marshall

Marshall Gambit in the Slav
Marshall Gambit in the Ruy Lopez
Marshall Defense against the Queen's Gambit (1. d4 d5 2. c4 Nf6?!)
Marshall Variation against the Sicilian (1. e4 c5 2. Nf3 e6 3. d4 d5)

Rubinstein

Rubinstein Variation against the French (...dxe4 and Nxe4)
Rubinstein Variation against the Budapest (1. d4 Nf6 2. c4 e5 3. dxe4 Ng4 4. Bf4)
Rubinstein Variation against the Nimzo-Indian (white plays e3, Nf3, Bd3)
Rubinstein Variation in the Four Knights
Rubinstein Variation in the English (1. c4 c5 2. Nc3 Nf6 3. g3 d5 4. cxd5 Nxd5 5. Bg2 Nc7)

Steinitz

Steinitz Defense against the Ruy Lopez (early d6)
Steinitz Variation in the Petroff Defense (3. d4)
the closed Sicilian is also called the Steinitz Variation
Steinitz Gambit is 1. e4 e5 2. Nc3 Nc6 3. f4


user167: I'm way late to the party here, but would nevertheless like to mention the contributions of the seventh world champion (and my favorite player) Vasily Smyslov. Here are some of his many eponymous systems and variations in major openings:

The Smyslov system in the Grünfeld Defense: 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Qb3 dxc4 6. Qxc4 O-O 7. e4Bg4, intending to follow up with ... Nfd7 and ... Nb6.
The Smyslov-Karpov variation in the Caro-Kann Defense: 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4Nd7.
The Smyslov system against the King's Indian Defense: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5.Bg5.
The Smyslov system in the English Two Knights: 1. c4 e5 2. Nc3 Nf6 3. g3Bb4.
The Smyslov defense in the mainline closed Ruy Lopez: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 O-O 8. c3 d6 9. h3h6, intending to continue with ... Re8 and ... Bf8, where the inclusion of ... h6 prevents a Bg5 pin.
Another Smyslov defense to the Ruy Lopez, featuring an early fianchetto: 1. e4 e5 2. Nf3 Nc6 3. Bb5g6.
The Smyslov variation in the Queen's Gambit Accepted: 1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3g6.
The Smyslov variation in the Slav Defense: 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4Na6 6. e4 Bg4.
The Reti-Smyslov variation of the King's Indian Attack: 1. Nf3 Nf6 2. g3 g6 3.b4.


user1239: Nimzovitch.

NimzoIndian Defense: 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 
Nimzovitch Defense: 1.e4 Nc6 
Nimzovitch Attack: 1.Nf3 d5  2.b3 (1.b3 is the Nimzo-Larsen Attack)

Nimzovitch Variations:

Sicilian Defense: 1.e4 c5 2.Nf3 Nf6 
Queens Indian Defense: 1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6
Falkbeer Counter-Gambit: 1.e4 e5 2.f4 d5 3.de5 c6
Falkbeer Counter-Gambit: 1.e4 e5 2.f4 d5 3.de5 c6 4.e4 Bb5+ *
Nimzovitch QP Defense: 1.d4 Nf6 (most sources attribute it to Bogoljubow)
Latvian Counter-Gambit: 1. e4 e5 2. Nf3 f5 3. Nxe5 Qf6 4. d4 d6 5. Nc4 fxe4 6. Ne3
Philidors Defense: 1. e4 e5 2. Nf3 d6 3. d4 Nf6
French Defense, Advance Var-Nimzovitch Var: 1. e4 e6 2. d4 d5 3. e5 c5 4. Qg4
French Defense, Nimzovitch (or Winawer) Var: 1. e4 e6 2. d4 d5 3. Nc3 Bb4
Four Kts Opening, Nimzovitch or Paulsen Var: 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 5. O-O O-O 6. Bxc6
English Opening, Nimzovitch Var: 1.c4 e5 2.Nf3
Benoni Defense, Nimzovitch or Kts Tour Var: 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. Nd2
Caro-Kann Defense, Nimzovitch or Tartakower Var: 1.e4 c6 2.d4 d5 3.Nc3 de4 4.Ne4 Nf6 5.Nf6+ ef6
Ruy Lopez, Steinitz Var - Nimzovitch Attack: 1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4 Bd7 5. Nc3 Nf6 6. Bxc6
English Opening - Four Kts Var - Nimzovitch Var: 1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e4
EO - Nimzo-English Opening: 1. c4 Nf6 2. Nc3 e6 3. Nf3 Bb4

Notes: Simon Winawer played the "Winawer Variation" of the French Defense once in his entire career; why it's named after him instead of Nimzovitch who really popularized it is a mystery (to me at least). And no, Winawer does not deserve the credit for playing it first (if he even did that) many openings are named after the masters who hammered out the theory of them and/or made them popular. Ergo the "Advance Variation" of the French Defense should also be named after Nimzovitch!
SOURCES: "The Oxford Companion To Chess" by David Hooper & Kenneth Whyld, 1984; p 226
http://www.chessvideos.tv/chess-opening-database/search/Nimzovich-variation
http://www.365chess.com/eco/C62_Ruy_Lopez_old_Steinitz_defence_Nimzovich_attack

47: <p>I always thought it was interesting that chess players had openings named after them.  The game of chess has only been popular and organized for about 150 years, yet all the most popular openings and most of their sub-variations have already been named, many after players from the 19th or early 20th centuries.  In five hundred years, will all these basic openings still be named after Morphy, Steinitz, Capablanca, and Lasker?  But I digress.</p>

<p>Which player has had the most openings or opening variations named after him?  My guesses would be Botvinnik or Aljechin (Alekhine).</p>
 103: <p>Using <a href="http://en.wikipedia.org/wiki/List_of_chess_openings_named_after_people" rel="noreferrer">Wikipedia</a> as a guide, I can see that Frank Marshall, Carl Schlecter and Akiba Rubinstein have about 5 opening variations named after them.</p>
 12: <p>Off the top of my head, there are a few players with multiple openings named after them:</p>

<h1><a href="http://en.wikipedia.org/wiki/Siegbert_Tarrasch" rel="nofollow noreferrer">Tarrasch</a></h1>

<ul>
<li>Tarrasch Variation against the French Defense</li>
<li>Tarrasch Opening against <code>d4</code> (with <code>...d5</code> and <code>...c5</code>)</li>
<li>the Open Variation in the Ruy Lopez is technically the Tarrasch</li>
</ul>

<h1><a href="http://en.wikipedia.org/wiki/Frank_Marshall_(chess_player)" rel="nofollow noreferrer">Marshall</a></h1>

<ul>
<li>Marshall Gambit in the Slav</li>
<li>Marshall Gambit in the Ruy Lopez</li>
<li>Marshall Defense against the Queen's Gambit (<code>1. d4 d5 2. c4 Nf6?!</code>)</li>
<li>Marshall Variation against the Sicilian (<code>1. e4 c5 2. Nf3 e6 3. d4 d5</code>)</li>
</ul>

<h1><a href="http://en.wikipedia.org/wiki/Akiba_Rubinstein" rel="nofollow noreferrer">Rubinstein</a></h1>

<ul>
<li>Rubinstein Variation against the French (<code>...dxe4</code> and <code>Nxe4</code>)</li>
<li>Rubinstein Variation against the Budapest (<code>1. d4 Nf6 2. c4 e5 3. dxe4 Ng4 4. Bf4</code>)</li>
<li>Rubinstein Variation against the Nimzo-Indian (white plays <code>e3</code>, <code>Nf3</code>, <code>Bd3</code>)</li>
<li>Rubinstein Variation in the Four Knights</li>
<li>Rubinstein Variation in the English (<code>1. c4 c5 2. Nc3 Nf6 3. g3 d5 4. cxd5 Nxd5 5. Bg2 Nc7</code>)</li>
</ul>

<h1><a href="http://en.wikipedia.org/wiki/Wilhelm_Steinitz" rel="nofollow noreferrer">Steinitz</a></h1>

<ul>
<li>Steinitz Defense against the Ruy Lopez (early <code>d6</code>)</li>
<li>Steinitz Variation in the Petroff Defense (<code>3. d4</code>)</li>
<li>the closed Sicilian is also called the Steinitz Variation</li>
<li>Steinitz Gambit is <code>1. e4 e5 2. Nc3 Nc6 3. f4</code></li>
</ul>
 167: <p>I'm way late to the party here, but would nevertheless like to mention the contributions of the seventh world champion (and my favorite player) <a href="http://en.wikipedia.org/wiki/Vasily_Smyslov" rel="noreferrer">Vasily Smyslov</a>. Here are some of his many eponymous systems and variations in major openings:</p>

<ul>
<li><p>The <em>Smyslov system</em> in the Gr&uuml;nfeld Defense: <code>1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Qb3 dxc4 6. Qxc4 O-O 7. e4</code><strong><code>Bg4</code></strong>, intending to follow up with <code>... Nfd7</code> and <code>... Nb6</code>.</p></li>
<li><p>The <em>Smyslov-Karpov variation</em> in the Caro-Kann Defense: <code>1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4</code><strong><code>Nd7</code></strong>.</p></li>
<li><p>The <em>Smyslov system</em> against the King's Indian Defense: <code>1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. Nf3 d6 5.</code><strong><code>Bg5</code></strong>.</p></li>
<li><p>The <em>Smyslov system</em> in the English Two Knights: <code>1. c4 e5 2. Nc3 Nf6 3. g3</code><strong><code>Bb4</code></strong>.</p></li>
<li><p>The <em>Smyslov defense</em> in the mainline closed Ruy Lopez: <code>1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 O-O 8. c3 d6 9. h3</code><strong><code>h6</code></strong>, intending to continue with <code>... Re8</code> and <code>... Bf8</code>, where the inclusion of <code>... h6</code> prevents a <code>Bg5</code> pin.</p></li>
<li><p>Another <em>Smyslov defense</em> to the Ruy Lopez, featuring an early fianchetto: <code>1. e4 e5 2. Nf3 Nc6 3. Bb5</code><strong><code>g6</code></strong>.</p></li>
<li><p>The <em>Smyslov variation</em> in the Queen's Gambit Accepted: <code>1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3</code><strong><code>g6</code></strong>.</p></li>
<li><p>The <em>Smyslov variation</em> in the Slav Defense: <code>1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4</code><strong><code>Na6 6. e4 Bg4</code></strong>.</p></li>
<li><p>The <em>Reti-Smyslov variation</em> of the King's Indian Attack: <code>1. Nf3 Nf6 2. g3 g6 3.</code><strong><code>b4</code></strong>.</p></li>
</ul>
 1239: <p>Nimzovitch.</p>

<ol>
<li>NimzoIndian Defense: <code>1.d4 Nf6 2.c4 e6 3.Nc3 Bb4</code> </li>
<li>Nimzovitch Defense: <code>1.e4 Nc6</code> </li>
<li>Nimzovitch Attack: <code>1.Nf3 d5  2.b3</code> (1.b3 is the Nimzo-Larsen Attack)</li>
</ol>

<p><strong>Nimzovitch Variations:</strong></p>

<ol start="4">
<li>Sicilian Defense: <code>1.e4 c5 2.Nf3 Nf6</code> </li>
<li>Queens Indian Defense: <code>1.d4 Nf6 2.c4 e6 3.Nf3 b6 4.g3 Ba6</code></li>
<li>Falkbeer Counter-Gambit: <code>1.e4 e5 2.f4 d5 3.de5 c6</code></li>
<li>Falkbeer Counter-Gambit: <code>1.e4 e5 2.f4 d5 3.de5 c6 4.e4 Bb5+ *</code></li>
<li>Nimzovitch QP Defense: <code>1.d4 Nf6</code> (most sources attribute it to Bogoljubow)</li>
<li>Latvian Counter-Gambit: <code>1. e4 e5 2. Nf3 f5 3. Nxe5 Qf6 4. d4 d6 5. Nc4 fxe4 6. Ne3</code></li>
<li>Philidors Defense: <code>1. e4 e5 2. Nf3 d6 3. d4 Nf6</code></li>
<li>French Defense, Advance Var-Nimzovitch Var: <code>1. e4 e6 2. d4 d5 3. e5 c5 4. Qg4</code></li>
<li>French Defense, Nimzovitch (or Winawer) Var: <code>1. e4 e6 2. d4 d5 3. Nc3 Bb4</code></li>
<li>Four Kts Opening, Nimzovitch or Paulsen Var: <code>1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 5. O-O O-O 6. Bxc6</code></li>
<li>English Opening, Nimzovitch Var: <code>1.c4 e5 2.Nf3</code></li>
<li>Benoni Defense, Nimzovitch or Kts Tour Var: <code>1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. Nd2</code></li>
<li>Caro-Kann Defense, Nimzovitch or Tartakower Var: <code>1.e4 c6 2.d4 d5 3.Nc3 de4 4.Ne4 Nf6 5.Nf6+ ef6</code></li>
<li>Ruy Lopez, Steinitz Var - Nimzovitch Attack: <code>1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4 Bd7 5. Nc3 Nf6 6. Bxc6</code></li>
<li>English Opening - Four Kts Var - Nimzovitch Var: <code>1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e4</code></li>
<li>EO - Nimzo-English Opening: <code>1. c4 Nf6 2. Nc3 e6 3. Nf3 Bb4</code></li>
</ol>

<p><strong>Notes</strong>: Simon Winawer played the "Winawer Variation" of the French Defense <strong>once</strong> in his entire career; why it's named after him instead of Nimzovitch who really popularized it is a mystery (to me at least). And no, Winawer <strong>does not</strong> deserve the credit for playing it first (if he even did that) many openings are named after the masters who hammered out the theory of them and/or made them popular. Ergo the "Advance Variation" of the French Defense should also be named after Nimzovitch!</p>

<p>SOURCES: "The Oxford Companion To Chess" by David Hooper &amp; Kenneth Whyld, 1984; p 226
<a href="http://www.chessvideos.tv/chess-opening-database/search/Nimzovich-variation" rel="noreferrer">http://www.chessvideos.tv/chess-opening-database/search/Nimzovich-variation</a>
<a href="http://www.365chess.com/eco/C62_Ruy_Lopez_old_Steinitz_defence_Nimzovich_attack" rel="noreferrer">http://www.365chess.com/eco/C62_Ruy_Lopez_old_Steinitz_defence_Nimzovich_attack</a></p>
