In his book, Technique For the Tournament Player, trainer Mark Dvorestky states that in most cases, conversion of an advantage takes place in the endgame.
An inadequate knowledge of endgame theory is one of the principled reasons why players fail to convert their advantage. In addition, if players do not know their way around theory, then the probability of mistakes sharply increases.
In my example, I have the following game (see picture on right):
It is Black to play (I'm Black).
It is well know that in BvN endgames it is true that the Bishop is stronger than the Knight because it is possible that the side with the Bishop can put the other side into zugzwang however, here it is slightly more difficult.
White just played 37. Kf3
What would you play as Black?
I gave this position a good long thought.
The only thing Black has get going is a passed d-pawn. Black's positional minuses are that White has a dark squared bishop and can attack Black's pawns on the kingside if Black is not careful.
In endgames it is extremely important that you minimise your opponent's counter-chances.
How then should Black proceed? The most important thing is to activate your king.
I played 33 ...b4
What I intend to do (see 2nd picture on right) is shuffle my king to the square d3 by taking advantage of the light squares or attack the pawn b2. White must do something to stop this.
38. Kf4 (White hopes to gain counterplay by breaking open the kingside) Kb5
39. b3 (well timed by White - White stops Black's progression by prevent Kc4/Ka4. White hopes that with the Black king "stuck" on the Queenside, White can march the pawns forward to win. Unfortunately, this meant....)
39... Nd2 (White had fatally weakened the b-pawn and is now subject to attack by the Knight)
40. g5 (White hopes to gain the initiative by breaking open the kingside pawn) Nxb3! (this moves was tricky to make. my first thought was to retake on g5 but I then realised, after some tempo calculation that I can get my queenside pawns moving much faster than White)
41. gxh6 gxh6
42. Be3 Nc5 (my kingside is close to collapsing if I'm not careful so I have to hurry to protect my kingside pawns)
43. Kf3 h5
44. Bg5! (A surprising move and one which I should have foreseen beforehand - see 3rd picture on right)
White has a very nasty trick. At the time, I was calculating tempi and I found that if I had taken the bishop with 44.... fxg5 45. hxg5, this might lead to a pawn race where Black queens the b-pawn and White queens the g-pawn (not the f-pawn of course because after 45... b3 46. f6 b2 47. f7 b1Q 48. f8Q Qf1+ ... winning the White Queen).
I thought the result is very unclear and creates unnecessary chances for my opponent. I chose the defend the f-pawn.
44... Ne4! (now White is in deep trouble. I am really threatening to take the Bishop with my f-pawn and recapturing the g-pawn with my Knight)
After this move, there is no defense for White and Black's b-pawn roams home.
After this game, I found that I could have taken the bishop with 44... fxg5 45 hxg5 as the Knight will have everything under control. after 45...Ne4 46. g7 Nf6. This just goes to show that I need to calculate better.