In the last week, Tournesol dev team announced an algorithm update (about scoring and recommendations). This change took place this morning with the weekly scores updates:

A "presumption of non-recommendability" is now implemented. By default a video's score is 0; to be recommended, the video's score must now reach a score of 20, which will require the inputs of at least 3 contributors.
See our paper

My personal observation:

Scores of videos changed a bit toward the +20 mark (higher have they score gone down (+60 before is now +45); lower have they score gone up (-25 before is now +0))

Even if scores changes, global ranking remain about the same, top 20 still contains what was here before

So from now, here is how we can read tournesol scores:

• More than +50 (before was More than +70): Top recommendation
• Between +40 & +50 (before was +50 to +70): Very good video
• Between +20 & +40 (before was +25 to +50): Good video
• Between 0 & +20 (before was -25 to +25): Average
• Below 0 (before was -50 to -25): Not recommended video