4...Bc5 5.c3 Nf6 6.e5 is variation 1 of 6 in the Scotch Gambit course, a intermediate opening course for White (ECO C44). It runs 21 moves and begins 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4 Bc5 …. Black guards the d4 pawn with the bishop. White offers another pawn with 5.c3. Black answers with the knight, and White pushes the e-pawn. After the trades on d2 White has more space and an easy game. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. e4 – White takes the centre and opens lines for the queen and the f1 bishop.
1... e5 – Black claims an equal share of the centre.
2. Nf3 – White develops and attacks the e5 pawn.
2... Nc6 – Black defends e5 and develops a knight.
3. d4 – White opens the centre at once. This is the Scotch.
3... exd4 – Black takes. This is by far the most common answer.
4. Bc4 – The Scotch Gambit. White develops first and takes the pawn back later. The bishop aims at f7.
4... Bc5 – The bishop guards the d4 pawn. Black wants to keep the extra pawn.
5. c3 – White offers a second pawn to open lines for the pieces.
5... Nf6 – The best answer. Black develops and attacks e4.
6. e5 – White pushes and chases the f6 knight.
6... d5 – The best answer. Black hits back in the centre and attacks the c4 bishop.
7. Bb5 – The bishop escapes and pins the c6 knight.
7... Ne4 – The knight jumps to a strong central square.
8. cxd4 – White takes back. The pawns on d4 and e5 give White more space.
8... Bb4+ – Black checks and offers a trade of bishops.
The lesson goes on for 5 more moves, each with its explanation.