Total including century after start of play, following plan (10)

'following plan' is the definition.
(following plans or tactics)

'total including century after start of play' is the wordplay.
'total' becomes 'tally' (synonyms).
'including' is an insertion indicator.
'century' becomes 'C' (common abbreviation).
'after' means one lot of letters go next to another.
'start of play' becomes 'act i' (Act I).
'c' after 'acti' is 'actic'.
'tally' placed around 'actic' is 'TACTICALLY'.