The starting point of IM Valeri Lilov's considerations is the position, arising after the moves 1.e4 e5 2.Nc3 Nf6.
Here White has the choice of how to proceed.
With 3. f4 White shows ambitions towards the black king, which Black counters best with d7-d5. The resulting position types are characterised by the fact that White often has the opportunity to win a pawn while Black has a development advantage in return. The resulting imbalance offers opportunities for both sides.
With 3.Bc4 White focuses on the development of his pieces.
Even the harmless-looking 3. g3 is not without poison. With the immediate d7-d5 Black achieves a balanced position that offers possibilities for both sides.
We have also summarised all the variations covered by Lilov in this replayer. Feel free to play around, activate the engine and test whether you develop a feeling for the position. If you like a variation, you can add it to your repertoire.