I recently played an instructive chess game at letsplaychess.com. I played an opening that I seldom use and was successful with it. My opponent was Likearocket from the United Kingdom. In this game he played white. Now I will provide the moves of the game along with my commentary.
1. e4 Nf6
I usually reply here with c5. My reply is known as the Alekhine Defence. It is a provocative move that encourages white to push his e-pawn in the hope that it will later prove to be overextended. The Alekhine Defence is considered a difficult opening. Black has to play very accurately because any mistake can prove fatal.
2. e5 Nd5
As I expect, black pushes his pawn.
3. d4 d6
I want to counter black's strong pawn centre.
4. c4 Nb6
White attacks my knight again.
5. Qf3 dxe
White's move is unusual. His knight would be better placed on f3 than his queen.
6. d5 c6
Black's decision not to recapture my e-pawn is a surprise.
7. c5 Nxd5
Black makes a mistake. He decides to attack my knight instead of capturing my pawn but ends up losing a pawn.
8. Nc3 g6
9. Bc4 Be6
10. Nxd5 Bxd5
11. Bxd5 cxd5
Now I have a strong pawn centre.
12. Ne2 Bg7
13. 0-0 Nc6
14. a3 0-0
15. b4 e4
My last move creates a double attack. My e-pawn attacks the white queen while my bishop attacks the white rook on a1.
16. Qb3 Bxa1
17. Bd2 Nd4
I attack the white queen with my knight because I want to exchange my knight for white's.
18. Nxd4 Bxd4
19. Bh6 Bh7
Again I want to exchange because I am ahead in material.
20. Bf4 e5
I strengthen my pawn centre.
21. Bd2 Kh8
I put my king on h8 to avoid any future checks from the white queen along the a2-g8 diagonal.
22. f3 f5
23. f4 exf
24. Bxf4 d4
My pawns dominate the centre of the board.
25. Bd6 Re8
White forces me to move my rook.
26. Kf2 Qh4+
White is worried about my pawns and wants to attack them but his king is too exposed on f2. I check him with my queen.
27. g3 Qxh2+
White makes a mistake which costs him a pawn. Here he should play Bg3 which forces me to move my queen.
28. Ke1 d3
White's move is forced. Now I threaten mate with my queen on e2.
29. Qd1 0-1
White moves his queen to prevent mate on e2 but then resigns. He sees that I can play Bc3+. Then he must block the check with his queen by playing Qd2. I then play Qxd2# so he resigns. He knows that he cannot prevent mate.
In this game I play an opening which I suspect white does not expect. I manage to take advantage of his mistakes, take control of the centre and eventually overwhelm his king. If the game had continued longer, I would have centralized my a8 rook but in this game it was not necessary.