The curious Urusov Gambit seems something of a gimmick. A great article on it appears here
[Event "Urusov Gambit"] [Site "Tehran IRI"] [Date "2016.10.28"] [Round "4.20"] [White "Mashmooli, Kian"] [Black "Nasri, Amin"] [Result "0-1"] [WhiteElo "2137"] [BlackElo "2248"] [ECO "C44"] [FEN ""] 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3
The same article observers "With that the opening fell into disfavour at the highest levels of master competition, and today it is mostly seen in club play, where it racks up quick scores against inexperienced or unprepared opponents."
Certainly there are many chess sites advocating its adoption as a quick way for WHITE to get ahead. It's considered a common 'opening trick' Yet "Estrin's analysis revealed, however, a possible equalizing method for Black (with Panov's 4....d5) and suggested that some of the deepest lines might end in equality with best play."
Even with (4....d5) it seems difficult for WHITE to re-obtain equality. The opening can evolve into a Two Knights Defense (with 4....Nc6), albeit with a pawn exchanged for tempo.
Does lack of play at senior levels really suggest the gambit is not sound? Does anyone know of GMs who favour such a gambit? And would anyone be able to take us through some of the possible lines from this point as WHITE?