The main purpose of this "Knight Sacrifice" was "Self Clearance," in order for the combination to work the Knight had to be moved out of the way. This was a "Sacrifice That Gives Check" and it was "Total." Black " "Had to Accept. since it was his "Only Legal Move."
2) Rxg6+ Kxg6
The second sacrifice in this combination is an "Exchange Sacrifice." White gives up his Rook for the enemy's Knight in order to "Reposition" his King, put it in a square where it can be mated.
3)Rg6 MATE The "Mating Net" is completed.
