Lazy when winning

Do you recognize this situation? You have a good position, your opponent is down on time and stressed out. You just have to play a few more moves to decide the game, and POW! Out of the blue, your opponent plays an unexpected, excellent, but objectively obvious move. Well, this happened to me in a game earlier this week.

My opponent was not too familiar with the specific opening theory, so he spent quite some time on the first few moves. As the position below was on the board, I had about 25 minutes left on the clock, and my opponent had about 2 minutes, so I had lots of time to find the best continuation. What do you think I played? What do you think I should have played?

Well, I felt the pressure against my f-pawn as well as a potential discovery against my rook. So I was considering different options to fend off the attack. I felt that I had my opponent off balance and the win was in sight, so I did not consider any other potential threats against my position. So I focused on the f-pawn and saw that Bf5 would block the file and keep him from entering with the queen. The knight cannot capture because of the deadly Rxe1+. I felt that this was good enough and wanted to increase the time pressure on my opponent. But I failed to see that Bf5 is a horrible game-losing blunder. After the obvious and devastating move Qc4+, black is busted.

So what can we learn from this? Well I learned two things. One is the power of knowing opening theory. My opponent spent a third of his time before move 10, and was way behind on the clock as the position became more complicated. The second and most important thing I take away from this game is the importance of analyzing the position thoroughly, even when convinced that the game is won. Let me rephrase that, especially when convinced that the game is won. It is all too easy to get cocky when you have an advantage, so the challenge is to lean back and finish the job properly. Doing lazy assessments of a position is never a good idea.