Complex sentence: But until 1947, there was no definition of what constituted a first-class match in Australia, and this merely formalised in Australia the broad definition devised in England in 1894.
Split into simpler sentences: But until 1947, there was no formal definition of what constituted a first-class match in Australia. The 1947 definition merely formalised in Australia the broad definition devised in England in 1894.