"Semi-presidential government" is about to celebrate its thirtieth birthday. The party will not take place in France, where Maurice Duverger in his book Echec au Roi (check to the king) gave birth to it. Never accepted in its birthplace, this stateless concept is nonetheless a successful product of exportation due to Duverger's article in the European Journal of Political Research.Three criteria define Duverger's concept: a government responsible before the Parliament, a President elected by a direct universal suffrage (or likely), the same having personal powers. Therefore "semi-presidential government" is said to be the child of Europe's parliamentary and United States' presidential forms of government. Refuse to recognize this child would be easy just by stressing out the conceptual variability of "semi-presidential government". Even if Maurice Duverger and his followers are here to blame, it would be insufficient, a mere check to the king. In order to checkmate this concept, it is necessary to make more substantial moves. "Semi-presidential government" has not classificatory intentions, a question which Duverger evacuates: the presidential form of government cannot be one of its parents. If "semi-presidential government" has a heuristic aim as Duverger and his followers advocate, the concept does not reach it: the criteria of "semi-presidential government" are not operative to explain how "semi-presidential countries'" political institutions work. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]