Not Quite Janus

 

Continuing my recent odd fascination with the opening line 1.e4 e5 2.Nf3 Nc6 3.Bc4 d5 (see "Jerome Gambit: Janus" and "Looking Back At Janus") I encountered the early Chess Preceptor: A New Analysis of The Openings of Games (1843) by C. F. De Jaenisch with a similar line of play 

1.e4 e5 2.Bc4 d5 

 FOURTH OPENING . This is a bad opening for him , and we only introduce it as one of the Counter - gambits which your opponent may essay. You do better to take P with B than with P (3.exd5 Nf6 he may also play 3...Bc5 4.Nc3 Bc5 and then ...c6 with the chance of acquiring one of certain strong lines of attack) 

3.Bxd5 Nf6 4.Nc3 Bb4 5.Nge2 c6 6.Bb3 Bg4 7.0-0 Bxc3 8.bxc3 Bh4 9.d3 You keep pawn and have a good game. At move 4, instead of 4.Nc3 you may play 4.Qf3 but you are thereby exposed to more attack 

It was interesting to find that Stockfish 17.1 (40 ply) evaluates 1.e4 e5 2.Nf3 Nc6 3.Bc4 d5 as about 4/10 of a pawn better for White than than it evaluates 1.e4 e5 2.Bc4 d5.