Sergash: Alexander Brede Kvisvik, born in 1984, was 17 years old and rated 2060 at the time of this game. He later became a FIDE master in 2012. Carlsen was 11 years old and had a rating of 2127 at that time.
<1.e4 c5 2.f4 d5 3.exd5 Nf6! 4.Bb5+ Bd7 5.Bxd7+ Qxd7▢ 6.c4 e6!=> The Grand-Prix Attack, not necessarily the most successful line, but can surprise a player sometimes. I could not see prior Carlsen games with this line, though he had met 2.Nf3, 2.c3 and 2.d4. The previous year, the same two players had met, playing the same colors, see B Kvisvik vs Carlsen, 2001, draw.
<7.Qe2> The most played move in chess History, but probably not the best. More commendable is 7.dxe6! Qxe6+ (or 7...fxe6 8.Nf3 Bd6! 9.Ne5 (Christian Cramer - Josef Kuhnert, Regionalliga SW Bayern 04-05 (league, Germany) 2005, round 9.4 - Pasing vs. Sonthofen, draw) Qd8!= Stockfish 9 - 64 bits POPCNT) 8.Qe2! Nc6 (or 8...Qxe2+ 9.Nxe2= Gunnar Uusi - Hillar Karner, Estonia Championship (USSR) in Tartu 1972, 1-0) 9.Qxe6+ (9.Nc3 Qxe2+ 10.Ngxe2= transposing in Gunnar Uusi - Hillar Karner, Estonia Championship (USSR) in Tartu 1972, 1-0) fxe6= Gerd Putzbach (2200) - Thorsten Stelting (2245), Hamburg Championship (West Germany) 1985, 0-1.
<7...Be7?! 8.dxe6! Qxe6 9.Qxe6! fxe6 10.Nf3 Nc6 ⩲> Seems logical and reasonable at first sight, but it is inferior to the main move 7.Bd6!= as in the game R W Smith vs P Beach, 1979, draw.
<11.0-0=> It is more precise to delay castling here (or not castle at all!) and play instead 11.Nc3 (Henryk Dobosz (2380) - Ildiko Madl (2185), Szolnok (Hungary) 1985, round 6, 1-0) Bd6!N 12.d3 0-0-0! 13.Be3 Ng4! 14.Bd2 Nb4 15.Ke2! ⩲ Stockfish 9 - 64 bits POPCNT.
<11...0-0-0 ⩲> 11...Bd6! 12,d3 (12.Ng5N Nd4! 13.Nc3= Stockfish 9 - 64 bits POPCNT) 0-0-0= Marek Pigula (2195) - Jan Zysko (2104), Polland Championship Under 18 2008 in Leba, round 4, 0-1.
<12.a4?!=> Weird move, intended to bring the queen rook into play. Development is better: 12.Nc3 ⩲ Stockfish 9 - 64 bits POPCNT.
<12...Rhf8= / ⩲> Better is 12...h6!= Stockfish 9 - 64 bits POPCNT.