Wow, that was hard to read. As with anything game shape related, you have to track minutes over a long period of time. The minutes from previous weeks matter (although, of course more recent weeks are given more weight).
Someone in my league was training game shape a lot last season. I noticed at one point because all his players seemed to consistently stay at proficient game shape (of course, he had nearly perfect minutes at the beginning of the season). But as the cup finals approached, he started playing his main players too much (90+ minutes). They still held at around 9 game shape the first week, but in subsequent weeks they dropped to levels closer to respectable.
Of course, I can't be sure if he stopped training game shape somewhere along the line.
Run of the Mill Canadian Manager