Quote Originally Posted by Stephen Asen View Post


You can make only one blunder... Apart from that the game was very good, bloody and contested... You simply had to think a bit more before moving that pawn... The catasrtophy that happened was simpy a chain reaction
A blunder that results in the loss of a piece without compensation will usually result in a defeat. See my second game with Ichigo for examples of minor position mistakes that result in loss of time and a weaker position, and how that builds up. See my game with Cambovenzi for examples of positional mistakes that result in loss of activity and coordination, and how that builds up. I have a game somewhere where a bog standard opening was transformed, and my entire game from thereon was centred on an undefended square on d5.

Here's the game. Note that after 8...c5, my immediate response was to swap off my black-square Bishop, which can't control the d5 square, with his Knight, which can. Once that was done, I had 2 pieces that could control that square, and he had 1, and a further exhange gave me uncontested control of that square, from which my Bishop controlled the later game.
Spoiler Alert, click show to read: 
[Event "Friendly Game"]
[Site "chesshere.com"]
[Date "2007.11.27"]
[White "pannonian"]
[Black "Feliks"]
[Result "1-0"]
[WhiteElo "1417"]
[BlackElo "1419"]

1. e4 e5 2. Nf3 d6 3. Bc4 Nf6 4. d3 Bg4 5. Be3 Bxf3 6. Qxf3 c6 7. Nc3
Qa5 8. O-O c5 9. Bg5 Nbd7 10. Bxf6 Nxf6 11. Nd5 O-O-O 12. Nxf6 gxf6 13.
Qxf6 Rg8 14. Bd5 Qd2 15. Rfd1 Qxc2 16. Rac1 Qxb2 17. Rb1 1-0


And here's how it might have continued. After the played moves above, the best Black can do is to obfuscate the attack with a Queen for Rook exchange (not appetising), but the below is fairly plausible if White doesn't want to lose his Queen. After 18...Rg7 defending against Qxb7 mate, the subsequent moves are forced. Note the Bishop dancing around the d5 square where it's immune from attack, and how the d6 pawn blocks in the black Bishop.

Spoiler Alert, click show to read: 
[Event "Friendly Game"]
[Site "chesshere.com"]
[Date "2007.11.27"]
[White "pannonian"]
[Black "Feliks"]
[Result "*"]
[WhiteElo "1406"]
[BlackElo "1431"]

1. e4 e5 2. Nf3 d6 3. Bc4 Nf6 4. d3 Bg4 5. Be3 Bxf3 6. Qxf3 c6 7. Nc3
Qa5 8. O-O c5 9. Bg5 Nbd7 10. Bxf6 Nxf6 11. Nd5 O-O-O 12. Nxf6 gxf6 13.
Qxf6 Rg8 14. Bd5 Qd2 15. Rfd1 Qxc2 16. Rac1 Qxb2 17. Rb1 Qe2 18. Qxf7 Rg7 19. Bxb7+ Kb8 20. Bd5+ Kc8 21. Be6+ Rd7 22. Qe8+ Kc7 23. Qb8+ Kc6 24. Bd5#


For following these games, I recommend Winboard.