This is a fresh idea played by many strong grandmasters in the last year.  The idea is to prepare the advance e2-e4 without fearing the check on b4. After the most principal answer 7…dc4 we have a surprise for Black 8.e3! A modern approach to the position where White opts for gambit play. Black bases his strategy on defending the pawn, while White gains compensation for the sacrificed pawn by centralizing both knights, occupying the important squares e4 and e5.