MHR is super accurate. It is a whole formula. You can read about their analytics on the site. It does go by the last 10 games. Obviously it fluctuates throughout the year.
But when you start that low it is so hard to move up significantly.
They explain the math at https://myhockeyrankings.com/news.php?b=305
You can look also click the "Rating Math" button on any team to see how they derived the score.
Come on man! My kids on a top 10 team. He’s got a 70% chance of making the show…right?