If clicking TV Tropes is too much work (or you fear a loss of productivity from TV Tropes, a reasonable fear...):
1.
All episodes are scored relative to the series they are in. A 5 is 'average' quality for a given series, as Chuck sees it; however this does not carry across series boundaries. A DS9 '5' could be considered to be a '10' for ENT, but this isn't ever actually the case; the score does not reflect some nebulous quantification of 'goodness'.
A: A score of 10 is one of the best, strongest episodes of a series.
B: 2 is the worst score for an unintentionally terrible episode.
C: Episodes with 1s are ones the creators had to
work to make terrible. An episode that scores a 1 implicitly makes the series worse by association.
D: Each series has one 'zero' score handed out for being terrible intentionally, and it making the series and Trek franchise worse by association. These are the worst of the worst.
2. Chuck employs a Smash Bros. Melee-like bonus system, for common Trek tropes.
A: Annoying Person - Nearly always granted for whoever did really dumb stuff in the episode
The Neelix Corollary: Stupid Neelix Moment - Applies only to Voyager. Neelix nearly always does idiotic, detrimental things, the only real question is what he's done. On the rare episode that he
hasn't done something, the episode is granted a +1 modifier to its final score.
B: Damn Dirty Mutant - Character transforms into something else.
C: Burn Baby Burn - Crashed ship.
D: Lazarus of the Week - Someone comes back from the dead.
The Tom Paris Corollary: Lt. Tom Paris is the only character ever to achieve a Jesus of the Week, for raising himself from the dead.
E: Ancient Chinese Secret - Anything from Earth history is referred to as 'ancient' regardless of what time that thing is from.
F: Twenty Dollar Bill - A character engages in or condones genocide. Thanks, Andrew Jackson!
G: Red Ring of Death - Holodeck malfunction
H: Cosmic Eggshell - Inspired by Discovery, this bonus is a newcomer. This bonus is gained by episodes where something really dumb threatens universal and/or multiversal existence.
I: Janeway Pie - Self-destruct is triggered. Often done by Kathryn 'I win because you lose' Janeway. Also inspired by the authorization code used to achieve said self-destruct: "Janeway Pi-1-1-0"
J: Cosmic Faceplant - A previously formidable entity is made into a joke. Often happens to the Borg.
K: Like Unto an Amoeba - The cast encounters a vastly more powerful lifeform. It's not unheard of for a Like Unto an Amoeba entity to suffer a Cosmic Faceplant!
L: Smack the Hell Up - An annoying character gets their duly deserved physical recompense.
M: You Can Go Home Again - Duplicate Earth, pretty much.
N: Unsafe at Any Speed - Starship that was clearly not vetted by OSHA.
O: I Am Legion - Possessed characters.
P: Bramha of the Week - A character creates a new sentient life, possibly unintentionally.
3. These are
Opinionated reviews. Chuck can dispense bonuses, scores, or whatever as he sees fit, because it's his show. The
MST3K Mantra is in full effect.
4. That being said, this system only really applies to Star Trek. Non-Trek works are entirely different.