Some chess endings which appear lost have hidden resources that produce fairly straightforward drawing sequences. Such was the case in the following Bishop versus Knight ending. White has three pawns on the squares g2, h3, and d4 along with Bishop at d5 an King at b4. Black has two pawns on the squares h6 and b6 along with King at f5 and the key blockading Horse at d6.
The Knight at d6 and pawn at b6 have an iron grip on the squares c4, c5, b5, and a5. This uncrossable/impassable complex of squares prevents the invasion of the wannabe marauding King at b4. With Black to move, his King can reach e3 suppressing any White Monarch endeavors to reach the King Side region. If White gets too frisky by advancing his King Side pawns, they will become vulnerable and ingested by hyperactive Black King.
This actually happened to the owner of the White pieces in this game, rolandBu of Luxembourg who pressed to hard and lost this 3 minute game at the Internet Chess Club. Bill Wall writing at chessmaniac.com writes lucidly about more difficult Knight Blockade/Fortress positions. One can faintly discern Bill’s chess mania and addiction when he was once uplifted by the fact he got wind of Bobby Fischer’s familiarity with him. Most USCF members are afflicted with this same type of obsession and I can relate with no disrespect intended towards the prolific output of Bill or his character.
Finally, a reward for playing tenacious defense is that you might be rewarded by reaching a position similar to the diagrammed AND your opponent might not be able to overcome the forward inertia of position that was probably once won. If he lurches to much, the defender might become the victor!