This paper examines the genesis of journal impact measures and how their evolution culminated in the journal impact factor (JIF) produced by the Institute for Scientific Information. The paper shows how the various building blocks of the dominant JIF (published in the Journal Citation Report – JCR) came into being. The paper argues that these building blocks were all constructed fairly arbitrarily or for different purposes than those that govern the contemporary use of the JIF. The results are a faulty method, widely open to manipulation by journal editors and misuse by uncritical parties. The discussion examines some solution offered to the bibliometrics and scientific communities considering the wide use of this indicator at present.