user16: I understand the theory, and have seen examples, of endgames where a pawn promoted to a queen creates a draw and instead the player typically promotes to rook. My question is, has this ever occurred in a game at the international level?
Instances of a pawn promoted to a knight would be interesting, but not really the target of this question. I am interested in notable games where a pawn was promoted to either a rook or a bishop.

user8860: Tim Krabbé has an extensive page on B- and R-promotions
in his Chess Curiosities site, including many examples
from actual play:
http://timkr.home.xs4all.nl/chess2/minor.htm

user587: There are a number of examples from international level games on this page: Practical Underpromotion
Here I have copied some of the more interesting ones. 
Vasuikov - Tukmakov, Erevan 1976
[FEN "8/5p2/4p3/4P3/4K1k1/7r/7p/7R w - - 0 1"]

1.Rg1+ hxg1=R! ( 1...hxg1=Q??= )

Simonson - Lasker, New York, 1892
[FEN "2k5/8/2PK4/P7/8/8/8/8 b - - 0 1"]
[StartFlipped "0"]

1...Kb8 2.Kd7 ( 2.c7+?? Kc8= ) 2...Ka8 3.c7 Ka7 4.c8=R! ( 4.c8=Q??= ) 

Badestein - Otto, Wernigerode 1952
[FEN "5R2/8/4k3/8/8/8/5p1K/6r1 b - - 0 1"]
[StartFlipped "0"]

1...f1=R! ( 1...f1=Q?? 2.Re8+ Kd6 ( 2...Kd7 3.Rd8+ Kxd8= ) ) 

Sokolsky - Ravinsky, USSR 1938 This is a very interesting game, but unfortunately, a lot of variations have been analysed, and unfortunately, I do not have the patience to convert them to PGN. :)

user167: Here's another example each of a rook promotion and a bishop promotion from actual play. Neither specific promotion was quite absolutely necessary (you'll see what I mean), but neither one was at all a superfluous underpromotion either.
In the game Sajtar-Benko (Budapest 1954), the following position was reached after 85...Kh6:
[FEN "8/5KP1/7k/8/6P1/8/8/8 w - - 0 1"]
[Result "1-0"]

1.g8=R! (1.g8=Q??=) (1.g8=B?? Kg5=) (1.g8=N+ Kg5 2.Nf6 $18) (1.g5+ Kxg5 2.g8=Q+ $18) Kh7 2.Rg6 Kh8 3.Rh6#

Here promotion to a queen is stalemate, while promotion to a bishop allows Black to capture the remaining pawn with a draw by insufficient material. So the only promotions that win here are 86.g8=N+ (which is a long, drawn out win after 86...Kg5 87.Nf6) and 86.g8=R!. Unfortunately, neither underpromotion is strictly necessary, as White could instead win more prosaically by just releasing the stalemate trap with, say, 86.g5+ followed by promotion to queen. But still, the rook promotion is the move Sajtar played, and it's also the best, yielding mate in three.
The next position is from the game Tomic-Winzbeck (Dortmund Open 1993):
[FEN "2rRb2k/2P4p/6pP/p2B1pP1/Pp2pP2/1P2K3/8/8 b - - 0 1"]
[StartFlipped "0"]
[Result "1-0"]

1...Rxd8 2.cxd8=B! (2.cxd8=Q?? $10) (2.cxd8=R?? $10) (2.cxd8=N $18) 2...Bf7 3.Bf6+ (3.Bxf7?? $10) 3...Kg8 4.Bxf7+ Kxf7 5.Bd8 $18

Black played 43...Rxd8, to which White responded 44.cxd8=B!, since promotion to either queen or rook would yield stalemate. Not unlike before, while promotion to anything stronger would give up a draw, it's also the case that the bishop promotion wasn't the only option: a knight promotion would win easily enough here too. Still, the bishop promotion was actually played, and is the most natural, immediately threatening 45.Bf6#. Black resigned after the promotion, but could have set up one more not-so-subtle trap by playing 44...Bf7, when 45.Bxf7?? would again be stalemate. White would instead need to play something like 45.Bf6+ Kg8 46.Bxf7+ Kxf7 47.Bd8 and win easily with the extra bishop.

This is a bit off-topic, but since we're talking bishop promotions, I can't resist mentioning another example from "actual play," this one the rather silly online blitz game Rybka-Nakamura (ICC 2008). The six bishop promotions in this game are of course entirely unnecessary, but the game itself is a good illustration of how an engine can go horribly wrong in a completely closed position in which it insists on trying to win with an entirely illusory material advantage that it has. The final position after 271...Bbc6#:
[FEN "K7/2bb4/1bbb4/3k4/8/8/8/8 w - - 0 1"]


user109: The wikipedia entry on promotion gives a position from a 2006 game at the Irish Chess Championship, in which a promotion to queen would allow stalemate:
[FEN "8/8/4Q3/8/5q2/8/1p2K2k/8 b - - 0 1"]
[StartFlipped "0"]

1...b1=R! $19 (1...b1=Q?? 2.Qh3+! Kxh3 $10)

The same entry also points to the 1972 game between Aron Reshko and Oleg Kaminsky, where promotion to a queen or rook would allow stalemate, and promoting to a knight would be insufficient to win:
[FEN "4Q3/Pq4pk/5p1p/5P1K/6PP/8/8/8 w - - 0 1"]

1.a8=B! (1.a8=Q?? Qf7+! 2.Qxf7 $10) (1.a8=R?? Qf7+! 2.Qxf7 $10) 1...Qb3 2.Qd7 $18

Rook and Bishop promotion is very rare in world class play.  Knight promotion is more common, but not as much as Queen promotion.  From the looks of it, it looks like Knight promotion is popular when promoting to any other piece would result in its immediate capture where as a Knight promotion would often be used to fork a King and a another piece resulting in material gain.

16: <p>I understand the theory, and have seen examples, of endgames where a pawn promoted to a queen creates a draw and instead the player typically promotes to rook. My question is, has this ever occurred in a game at the international level?</p>

<p>Instances of a pawn promoted to a knight would be interesting, but not really the target of this question. I am interested in notable games where a pawn was promoted to either a rook or a bishop.</p>
 8860: <p>Tim Krabbé has an extensive page on B- and R-promotions
in his Chess Curiosities site, including many examples
from actual play:</p>

<p><a href="http://timkr.home.xs4all.nl/chess2/minor.htm">http://timkr.home.xs4all.nl/chess2/minor.htm</a></p>
 587: <p>There are a number of examples from international level games on this page: <a href="http://timkr.home.xs4all.nl/chess2/minor.htm" rel="nofollow noreferrer">Practical Underpromotion</a></p>

<p>Here I have copied some of the more interesting ones. </p>

<p><strong>Vasuikov - Tukmakov, Erevan 1976</strong></p>

<pre><code>[FEN "8/5p2/4p3/4P3/4K1k1/7r/7p/7R w - - 0 1"]

1.Rg1+ hxg1=R! ( 1...hxg1=Q??= )
</code></pre>

<p><strong>Simonson - Lasker, New York, 1892</strong></p>

<pre><code>[FEN "2k5/8/2PK4/P7/8/8/8/8 b - - 0 1"]
[StartFlipped "0"]

1...Kb8 2.Kd7 ( 2.c7+?? Kc8= ) 2...Ka8 3.c7 Ka7 4.c8=R! ( 4.c8=Q??= ) 
</code></pre>

<p><strong>Badestein - Otto, Wernigerode 1952</strong></p>

<pre><code>[FEN "5R2/8/4k3/8/8/8/5p1K/6r1 b - - 0 1"]
[StartFlipped "0"]

1...f1=R! ( 1...f1=Q?? 2.Re8+ Kd6 ( 2...Kd7 3.Rd8+ Kxd8= ) ) 
</code></pre>

<p><strong>Sokolsky - Ravinsky, USSR 1938</strong> This is a very interesting game, but unfortunately, a <em>lot</em> of variations have been analysed, and unfortunately, I do not have the patience to convert them to PGN. :)</p>
 167: <p>Here's another example each of a rook promotion and a bishop promotion from actual play. Neither specific promotion was <em>quite</em> absolutely necessary (you'll see what I mean), but neither one was at all a superfluous underpromotion either.</p>

<p>In the game <a href="http://www.chessgames.com/perl/chessgame?gid=1271474" rel="noreferrer">Sajtar-Benko (Budapest 1954)</a>, the following position was reached after <code>85...Kh6</code>:</p>

<pre><code>[FEN "8/5KP1/7k/8/6P1/8/8/8 w - - 0 1"]
[Result "1-0"]

1.g8=R! (1.g8=Q??=) (1.g8=B?? Kg5=) (1.g8=N+ Kg5 2.Nf6 $18) (1.g5+ Kxg5 2.g8=Q+ $18) Kh7 2.Rg6 Kh8 3.Rh6#
</code></pre>

<p>Here promotion to a queen is stalemate, while promotion to a bishop allows Black to capture the remaining pawn with a draw by insufficient material. So the only promotions that win here are <code>86.g8=N+</code> (which is a long, drawn out win after <code>86...Kg5 87.Nf6</code>) and <code>86.g8=R!</code>. Unfortunately, neither underpromotion is strictly necessary, as White could instead win more prosaically by just releasing the stalemate trap with, say, <code>86.g5+</code> followed by promotion to queen. But still, the rook promotion is the move Sajtar played, and it's also the best, yielding mate in three.</p>

<p>The next position is from the game <a href="http://www.chessgames.com/perl/chessgame?gid=1287069" rel="noreferrer">Tomic-Winzbeck (Dortmund Open 1993)</a>:</p>

<pre><code>[FEN "2rRb2k/2P4p/6pP/p2B1pP1/Pp2pP2/1P2K3/8/8 b - - 0 1"]
[StartFlipped "0"]
[Result "1-0"]

1...Rxd8 2.cxd8=B! (2.cxd8=Q?? $10) (2.cxd8=R?? $10) (2.cxd8=N $18) 2...Bf7 3.Bf6+ (3.Bxf7?? $10) 3...Kg8 4.Bxf7+ Kxf7 5.Bd8 $18
</code></pre>

<p>Black played <code>43...Rxd8</code>, to which White responded <code>44.cxd8=B!</code>, since promotion to either queen or rook would yield stalemate. Not unlike before, while promotion to anything stronger would give up a draw, it's also the case that the bishop promotion wasn't the only option: a knight promotion would win easily enough here too. Still, the bishop promotion was actually played, and is the most natural, immediately threatening <code>45.Bf6#</code>. Black resigned after the promotion, but could have set up one more not-so-subtle trap by playing <code>44...Bf7</code>, when <code>45.Bxf7??</code> would again be stalemate. White would instead need to play something like <code>45.Bf6+ Kg8 46.Bxf7+ Kxf7 47.Bd8</code> and win easily with the extra bishop.</p>

<hr>

<p>This is a bit off-topic, but since we're talking bishop promotions, I can't resist mentioning another example from "actual play," this one the rather silly online blitz game <a href="http://www.chessgames.com/perl/chessgame?gid=1497429" rel="noreferrer">Rybka-Nakamura (ICC 2008)</a>. The six bishop promotions in this game are of course entirely unnecessary, but the game itself is a good illustration of how an engine can go horribly wrong in a completely closed position in which it insists on trying to win with an entirely illusory material advantage that it has. The final position after <code>271...Bbc6#</code>:</p>

<pre><code>[FEN "K7/2bb4/1bbb4/3k4/8/8/8/8 w - - 0 1"]
</code></pre>
 109: <p>The <a href="http://en.wikipedia.org/wiki/Promotion_%28chess%29#Promotion_to_rook_or_bishop" rel="noreferrer">wikipedia entry on promotion</a> gives a position from a 2006 game at the Irish Chess Championship, in which a promotion to queen would allow stalemate:</p>

<pre><code>[FEN "8/8/4Q3/8/5q2/8/1p2K2k/8 b - - 0 1"]
[StartFlipped "0"]

1...b1=R! $19 (1...b1=Q?? 2.Qh3+! Kxh3 $10)
</code></pre>

<p>The same entry also points to the 1972 game between Aron Reshko and Oleg Kaminsky, where promotion to a queen or rook would allow stalemate, and promoting to a knight would be insufficient to win:</p>

<pre><code>[FEN "4Q3/Pq4pk/5p1p/5P1K/6PP/8/8/8 w - - 0 1"]

1.a8=B! (1.a8=Q?? Qf7+! 2.Qxf7 $10) (1.a8=R?? Qf7+! 2.Qxf7 $10) 1...Qb3 2.Qd7 $18
</code></pre>

<p>Rook and Bishop promotion is very rare in world class play.  Knight promotion is more common, but not as much as Queen promotion.  From the looks of it, it looks like Knight promotion is popular when promoting to any other piece would result in its immediate capture where as a Knight promotion would often be used to fork a King and a another piece resulting in material gain.</p>
