The English Opening, and as response the Jaenisch Gambit. Chess.com has this to say: * It takes the c4 pawn off of a place where it attacks d5 It immediately allows one to fiancetto the c8 bishop if one is so inclined * the hole at b5 can be used sometime in the future to place the rook behind and attack with * It allows for an open, tactical game from the outset with its own unique character; the positions in which can be quite striking and fun to play * It will catch the English player off guard
2. e4 Bc8b7
Both advanced pawns under threat. The obvious defenses don't easily work; d3 bxc4 ; or Nc3 b5; or e5, and the black bishop gets even stronger. Maybe Qc2?
? The bishop has two jobs and can't do them both; g2 is weakened and the white queen's bishop blocked.
3... bxc4 4. Bd3e2
? Either Bc2 or Bxc4. This one just loses the e-pawn.
4... Bb7xe4 5. Be2f3
Necessary. Nf3 could've been better.
? Invites an exchange, or if declined, prepares d5.
6. d3 cxd3 7. Qd1xd3 Ng8f6
White has edge in development, black hurries to catch up.
8. Nb1c3 e5 9. Bc1g5 h6 10. Bf3xc6
Gives black a tempo.
10... Nb8xc6 11. Bg5xf6 Qd8xf6 12. Nc3d5
! The black queen has to protect c7. d6 is not a good square for it.
Invites Nxb4 Bxb4 Qe5 Nc6 Nf3, for an endgamish situation except for the black advantage in pawns.