So when you say “damn close to 100” is that 99.8? 95.1? Looking for some context here.
You're missing the point here. When there's just an image of a trend-wave graph, the best you can do is eyeball it and estimate. If it's an actual graph output where you can click on points and get details, you can get the level of precision you mention. But in many cases, it's definitely above 95.
There might be post-game outputs where you can see the "win probability" at every critical point of the game. I generally don't go searching for those.