[2] The opening first came to public prominence, however, after being adopted twice by Boris Spassky in his 1966 World Championship match against Tigran Petrosian[3][4] (after which the setup was dubbed the "Hippopotamus" by commentators).

[6] Prominent players to have adopted the Hippopotamus on an occasional basis in more recent years include Vlastimil Hort, Igor Glek, Mihai Suba, Tony Miles, Gata Kamsky, Pavel Blatny and Luke McShane.

Despite having achieved an ideal classical development White now faces a dilemma in terms of how to proceed, as Black has pawn control of every square on the fifth rank (a5–h5).

Black will likely proceed with either (a) the thematic King’s Indian pawn break ...f7–f5 (usually following ...0-0), or (b) the typical Hippo idea of ...g6–g5 and ...Ne7–g6–f4, either of which plans may result in a kingside attack.

To allow the various options given above, Black’s main objective in the early stages will be to remain flexible, including by delaying any decision about castling until after the central pawn structure has been defined.

White must also be wary of playing in too aggressive a fashion or of overextending, after which the dynamism of Black's seemingly passive structure may quickly become apparent (see, for example, Barczay vs. Ivkov, below).