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?
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 *
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.