Complex sentence: Note that many scorecards in the 18th century are unknown or have missing details and so it is impossible to provide a complete analysis of batting performances: e.g., the missing not outs prevent computation of batting averages.
Split into simpler sentences: Note that many scorecards in the 18th century are unknown or have missing details and so it is impossible to provide a complete analysis of batting performances. For example, the missing not outs prevent computation of batting averages.