The importance of the CYK algorithm stems from its high efficiency in certain situations. Using Big O notation, the worst case running time of CYK is O ( n 3 ⋅ | G | ) {\displaystyle {\mathcal {O}}\left(n^{3}\cdot \left|G\right|\right)} , where n {\displaystyle n} is the length of the parsed string and | G | {\displaystyle \left|G\right|} is the size of the CNF grammar G {\displaystyle G} (Hopcroft & Ullman 1979, p. 140). This makes it one of the most efficient parsing algorithms in terms of worst-case asymptotic complexity, although other algorithms exist with better average running time in many practical scenarios.