{The unreasonable effectiveness of pattern generation} {Petr Sojka, Ond\v{r}ej Sojka} {Languages are constantly evolving organisms and so are the hyphenation rules and needs. The effectiveness and utility of \TeX's hyphenation has been proven by its usage in almost all typesetting systems in use today. The current Czech hyphenation patterns were generated in 1995 and no hyphenated word database is freely available. We have developed a new Czech word database and have used \texttt{patgen} to efficiently generate new effective Czech hyphenation patterns and evaluated its generalization qualities. We have achieved almost full coverage on the training dataset of 3,000,000 words and validated the patterns on the testing database of 100,000 words approved by Czech Academy of Science linguists. Our pattern generation case study serves as an example of an effective solution of widespread dictionary problem. The study has shown the versatility of Liang's approach. The unreasonable effectiveness of \TeX's pattern technology has lead to applications that are and will be used even more widely 40 years after its inception.}