Caldwell College conducted by Columbia Academy, the students handed in their homework assignments. Everyone solved the chess problem correctly.
Next I presented, at the demonstration board, a game between Tigran Petrosian and Bobby Fischer where Fischer as Black played the King's Indian Defense (KID). Fischer allowed Petrosian's pawns to occupy the center squares, only to immobilize and attack the pawns. Think of the center squares as a bridge. The two armies fight for control of the bridge. The army that gains control of the bridge can invade into enemy territory. In the KID, Black lets the white pawns occupy the bridge but does not allow the pawns to cross the bridge. Fischer's pawns attacked Petrosian's pawns on e4, d5, and c4 from the f5, c6, and b5 squares respectively.
Then I began teaching simple endgames. In king and pawn endings, having the opposition is the difference between a win and a draw. The defending player's king must oppose the attacking player's king to keep it away from the queening square. In rook and pawn endings, the defending player should aim for the Philidor drawing position with king in front of the pawn and rook guarding the defender's third rank.
Finally I showed checkmates involving king and queen versus king, king and rook versus king, king and two bishops versus king, and king and bishop and knight versus king. The winning technique is always the same: drive the enemy king into the corner. The ending of king and two knights versus king is not a forced win, if the defender keeps his king away from the corner. When driving the king into the corner, beware of stalemates. Make sure that the king has at least one legal move.
Next class, I will discuss endgames that are more complicated.