user4531: I remember a recent(1-2 years) drawn (super)grandmaster game in which white had 2 connected pawns and a rook, while black had a rook. I later learned that it was a theoretical draw, which quite surprised me, since I had always though that two connected pawns should win. 
Does anyone remember this game? Are their similar positions? 

user7297: Two connected pawns usually win, but with a+b pawns, there are some positions which are drawn. I do not know which game you're referring to, but here are some examples:
[fen "8/8/8/3k4/pr6/4R3/1p6/1K6 b - - 0 0"]

(Black to move, from Black's point of view - I forgot how to flip the board.)
The black king is cut off on the third row, while the black rook is tied to the defense of the b-pawn.

[fen "8/8/p7/rp6/6R1/3k4/1K6/8 w - - 0 0"]

(White to move)
This one is even easier; white just keeps his king on b2 and his rook on the fourth row.

user167: I don't know the game you have in mind, but the following is one example of such a drawn position in this ending (as can be verified with a tablebase query):
[fen "8/8/1r4kP/6P1/2R2K2/8/8/8 w - - 0 1"]

White has no winning way to break the blockade and make progress. If the blockade is one rank further up the board, though, it can be broken straightforwardly:
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "8/1r4kP/6P1/2R2K2/8/8/8/8 w - - 0 1"]

1.Kg5 Ra7 2.Rf5 Rb7 3.Rf7+ Rxf7 4.gxf7 *


4531: <p>I remember a recent(1-2 years) drawn (super)grandmaster game in which white had 2 connected pawns and a rook, while black had a rook. I later learned that it was a theoretical draw, which quite surprised me, since I had always though that two connected pawns should win. 
Does anyone remember this game? Are their similar positions? </p>
 7297: <p>Two connected pawns usually win, but with a+b pawns, there are some positions which are drawn. I do not know which game you're referring to, but here are some examples:</p>

<pre><code>[fen "8/8/8/3k4/pr6/4R3/1p6/1K6 b - - 0 0"]
</code></pre>

<p>(Black to move, from Black's point of view - I forgot how to flip the board.)
The black king is cut off on the third row, while the black rook is tied to the defense of the b-pawn.</p>

<hr>

<pre><code>[fen "8/8/p7/rp6/6R1/3k4/1K6/8 w - - 0 0"]
</code></pre>

<p>(White to move)
This one is even easier; white just keeps his king on b2 and his rook on the fourth row.</p>
 167: <p>I don't know the game you have in mind, but the following is one example of such a drawn position in this ending (as can be verified with a <a href="http://www.k4it.de/?topic=egtb&amp;lang=en">tablebase query</a>):</p>

<pre><code>[fen "8/8/1r4kP/6P1/2R2K2/8/8/8 w - - 0 1"]
</code></pre>

<p>White has no winning way to break the blockade and make progress. If the blockade is one rank further up the board, though, it can be broken straightforwardly:</p>

<pre><code>[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[FEN "8/1r4kP/6P1/2R2K2/8/8/8/8 w - - 0 1"]

1.Kg5 Ra7 2.Rf5 Rb7 3.Rf7+ Rxf7 4.gxf7 *
</code></pre>
