This sacrifice belongs to a class of combinations Euwe described as “break-up combinations.” By that he meant combinations where the King is exposed by the elimination of its protective P-cover, the g and h-Pawns.
Euwe lists five factors that need to be present for the double B sacrifice to work:
1) One Rook must be immediately available
2) The victims pieces must be unable to support the defense
3) The K cannot escape via the f-files
4) Refusal of the second B sacrifice must have serious disadvantages
5) Material at the end of the combination must be favorable to the side making the sacrifices.
In the following classic game Tarrasch caught Nimzovich totally off guard with the double B sacrifice and the game is instructive because we see all five of the criteria being met.