So I mapped Cam's usage in the first 7 games this year versus the last 7 games last year to see how Fitz is using him.
Excluding Round 1 (William HIA) and Round 3 (Hunt sin bin) Fitz has been pretty consistent when using him off the bench. The idea seems to be to bring him on between the 20 and 30 minute mark, and either leave him or give him a very short rest at the back end of the game if there happens to be some spare interchanges.
The questions are whether his better performances were a result of this change, and/or whether the change has been made deliberately by Fitz with McInnes in mind. Both are possible I guess - but it is also possible that Fitz is trying to balance his minutes better in general and McInnes just pulled his finger out and played better.
