It is easy to see how many times each videos on YouTube were watch but we can’t know how it was watched. However YouTube knows how it was watched so it comes with a fair way to rank those videos. It is not about how many times it was watched but it is the duration it was watched.
Do you know that not many people watch the entire thing? It was counted one as well. Some videos might look interesting due to the thumbnail or the title which can fool viewers to click on it but just a few seconds they stop watching it. It is actually not fair.
In short, YouTube ranks videos by its duration of watch not watch counts.
Here is the official word by YouTube:
The experimental results of this change have proven positive — less clicking, more watching. We expect the amount of time viewers spend watching videos from search and across the site to increase. As with previous optimizations to our discovery features, this should benefit your channel if your videos drive more viewing time across YouTube.
Yesterday, we added new Time Watched reporting to YouTube Analytics, so now you have even more tools to evaluate the performance of your videos and channel. So keep making great videos that your fans will love and share, and encourage them to discover more of what YouTube offers, and you’ll see your own fan base grow, too.