An quick guide to explain what you're seeing :)
Here is some Explanation About Youtube Metrics.
Watchtime is your most important variable, you need literaly try to nail your viewers in your video !
SEO means Search Engine Optimization, and Youtube is the 2nd of the world (Google 1st), you need to work hard in some variables around your video like: Title, Description And Tags, Not even the greater is the better.
From 0 to 33: Weak SEO
From 34 to 53: You're starting to think as a winner.
From 54 to 73: Straight SEO. Keep this work and improve it.
From 74 to 89: A Very Good SEO. You Understand it.
From 90 to 99: Are you from Google ?
Your video content is your great thing, here we really work hard, we find water on the stones to give you a fair score, so... what we test ?
All Youtube factors to Rank a Video like: Channel Authority, Watchtime, Likes, Subscribers, Shares, Favorites, Comments, Video Quality, Captions, Dislikes, Age, Lenght etc. Many many things !
From 0 to 33: Very weak video. Your content its not interesting.
From 34 to 51: Weak Content. Some Improvements are Needed.
From 52 to 73: The World Youtube Line. Almost All Normal and Newest Good Videos Are here.
From 74 to 89: Very Good Content. Keep Working this way and better.
From 90 to 99: A Fucking Good Video, An Viral or Pop Artist Success.
If your video is your precious, your channel is where you put your precious, what we test on channel ?
A Channel basically have 5 factors: Total Watchtime, Subscribers, Age, Videos Quantity and Social Presence.
From 0 to 23: A Very New or Poor Content Channel. Very Weak.
From 24 to 53: You are starting to think seriously became an youtuber.
From 54 to 73: You have an Good Channel. Keep it Growing !
From 74 to 83: The World Famous Line, Here you became to gain some money online and offline.
From 84 to 99: Man, Youtube Needs Your Channel.
Social is the easiest score here, if you have so much shares, likes, favs, comments in social medias you are higher ranked here. Easy not ?. Not.
From 0 to 13: A very weak social presence
From 14 to 33: You are doing a Straight job, but you can do it better.
From 34 to 63: You probally have a good social presence, but don't forget to keep growing.
From 64 to 83: Very Good, Many People knows you. Great Work !
From 84 to 99: Bro, You are a Star.
Well, if you apply these tips and steps in your video and channel, your success is coming. see you :)