The classic bishop sacrifice (also known as the Greek gift sacrifice) is the oldest and most studied of the sacrifices and has been already studied by Greco (1619). Through practice, certain conditions that are necessary for a successful attack or a successful defence were established.
Conditions for the attacking side: Bishop is sacrificed on h7, the knight must be in the range of g5 square, the queen must be in reach of h5 square or diagonal b1-h7.
For the defending side there are also known conditions: the knight must be in reach of square f6 or queen/bishop must be on the b1-h7 diagonal. The worst square for the rook is usually f8 since it prevets black king from escaping to the center.
The defending side usually has 4 options after the classic bishop sacrifice:
- withdrawal of the king to g8: defending side usually can defend h7 square with the knight (from f6 or f8) or puts bishop/queen on the diagonal b1 - h7.
- withdrawal of the king to g6: when the withdrawal Kg8 is not good, the defending side usually reaches for Kg6.
- withdrawal of the king to h6: the attacking side usually does not have a dark square bishop (on c1-h6 diagonal) and it has a pawn on h4, which prevents Qg4, Qh4 maneouvres.
- declining the sacrifice: the attacking side does not bring new pieces to attack with a tempo (f.e. Ng5+ or Qh5+) and the defending side uses this tempo for a counter attack, exchange of the attacking pieces, etc..