You might remember our old engagement graphs from the ancient days of Stats 1.0. They were great, but they could be confusing -- people wondered why sometimes, areas of the graph exceeded 100%. It all made sense once we explained, but with Stats 2.0, we figured we'd remove the extra step in understanding and make these graphs more intuitive (as well as more informative).
This new engagement graph separates watches from rewatches (the former graphs were basically the top line of this graph). The first view by an individual of any part of the video is counted in the blue portion of the graph, while any subsequent views are counted in the orange (so take note: 16 views worth of orange could be one person watching 16 times, four people watching four times, or 16 individual rewatches -- you can come to further conclusions in the individual heatmaps).
With the new engagement graphs, you can tell more than ever which parts of your videos are the most engaging, whether it's because they're the most interesting and most confusing, and continue to improve the videos you make in the future based on this information. Happy analyzing!