Recently, I was browsing IMDb’s list of top-rated TV shows:

According to IMDb ratings, Planet Earth II is the second-best TV show of all time, with 9.5 stars out of 10. But if you look at the ratings of each individual episode, they range from 6.8 to 7.91:

In general, the rating of a TV show usually differs from the average rating of that show’s episodes. What does the list of top TV shows look like if we sort by average episode rating instead of show rating? Perhaps voters have different motivations when they’re rating shows than when they’re rating individual episodes, and it could be interesting to see how the ratings differ.

This list shows the top 250 TV shows, ordered by average episode rating: (click the button to expand the list)

We immediately run into a problem with this list: it’s dominated by little-known shows that only have about five votes per episode. If an episode has five votes, even if they’re all 10-star ratings, I wouldn’t feel confident that it really deserves 10 stars–perhaps if more people watched the show, most of them wouldn’t like it.

There’s a known solution to this problem, which IMDb used to implement. (Their new ranking algorithms are more sophisticated (and secret), but the old system is good enough for us.)

Intuitively, the more votes a show has, the more trustworthy its rating. We can formalize the intuition with this formula:

rating = (v / (v + m)) * r + (m / (v + m)) * c

where

r is the unweighted rating of the episode;

c is the average rating across all episodes;

v is the number of votes;

m is the vote minimum.

In effect, it’s as if we give every TV episode m extra votes at the average rating. If we use m = 1000, then an episode with only five votes will have a weighted score that’s close to the average across all episodes; whereas for an episode with 10,000 votes, the 1000 extra votes won’t matter much.

This table displays the top 250 TV shows using this weighting algorithm, where m = 1000 and the average episode rating is 7.4. For comparison, I calculated the list of top TV shows using the same weighting algorithm3, but with a 25,000-vote minimum (shows have a higher vote minimum because they tend to get a lot more votes than episodes). The table displays the episode-based ranking on the left and the show-based ranking on the right. Click “Expand” to view:

Title (episode-ranking) Rating Title (show-ranking) Rating
1 Chernobyl 9.6 Breaking Bad 9.5
2 Game of Thrones 8.8 Chernobyl 9.4
3 Breaking Bad 8.8 Game of Thrones 9.4
4 Daredevil 8.8 Band of Brothers 9.4
5 Sherlock 8.8 Rick and Morty 9.1
6 Attack on Titan 8.8 The Wire 9.1
7 Stranger Things 8.7 Planet Earth 9.1
8 Les Synaudes 8.6 Sherlock 9.0
9 The Leftovers 8.6 The Sopranos 9.0
10 Hannibal 8.6 Avatar: The Last Airbender 9.0
11 Person of Interest 8.5 Planet Earth II 9.0
12 Vader: A Star Wars Theory Fan Series 8.5 True Detective 8.9
13 When They See Us 8.5 Cosmos 8.9
14 True Detective 8.5 Fargo 8.9
15 Sense8 8.5 Friends 8.8
16 BoOzy' OS 8.5 Stranger Things 8.8
17 The Punisher 8.5 Firefly 8.8
18 Band of Brothers 8.4 Death Note 8.8
19 Lost 8.4 Black Mirror 8.8
20 Narcos 8.4 House of Cards 8.7
21 Shadowhunters 8.4 Leyla and Mecnun 8.7
22 Firefly 8.4 Westworld 8.7
23 Dexter 8.3 The Office 8.7
24 The Sopranos 8.3 Narcos 8.7
25 Twin Peaks 8.3 Arrested Development 8.7
26 One Punch Man 8.3 Seinfeld 8.7
27 Fawlty Towers 8.3 Fullmetal Alchemist: Brotherhood 8.7
28 Friends 8.2 Peaky Blinders 8.6
29 24: Live Another Day 8.2 Dexter 8.6
30 Doom Patrol 8.2 House 8.6
31 Sons of Anarchy 8.2 The Filthy Frank Show 8.6
32 Code Black 8.2 The Simpsons 8.6
33 Freaks and Geeks 8.2 Daredevil 8.6
34 House 8.2 Twin Peaks 8.6
35 Banshee 8.2 South Park 8.6
36 The Adventures of Sherlock Holmes and Dr. Watson 8.2 Rome 8.6
37 Black Sails 8.2 Better Call Saul 8.6
38 Forever 8.2 One Punch Man 8.6
39 Penny Dreadful 8.2 Attack on Titan 8.6
40 The Legend of Korra 8.2 Freaks and Geeks 8.6
41 Bodyguard 8.2 TVF Pitchers 8.6
42 Twin Peaks 8.2 Doctor Who 8.5
43 The Originals 8.1 The X-Files 8.5
44 Ash vs Evil Dead 8.1 The Twilight Zone 8.5
45 Master of None 8.1 Shameless 8.5
46 Avatar: The Last Airbender 8.1 It's Always Sunny in Philadelphia 8.5
47 Bates Motel 8.1 Cowboy Bebop 8.5
48 The OA 8.1 Batman: The Animated Series 8.5
49 Gotham 8.1 Vikings 8.5
50 Gravity Falls 8.1 Downton Abbey 8.5
51 Sharp Objects 8.1 Battlestar Galactica 8.5
52 11.22.63 8.1 Last Week Tonight with John Oliver 8.5
53 Boardwalk Empire 8.1 Pride and Prejudice 8.5
54 Teen Wolf 8.1 Sons of Anarchy 8.5
55 The Defenders 8.1 Archer 8.5
56 Feud 8.1 Dark 8.5
57 Luther 8.1 The Haunting of Hill House 8.5
58 Mad Men 8.1 Six Feet Under 8.5
59 The Newsroom 8.1 Fawlty Towers 8.5
60 Community 8.1 Mad Men 8.5
61 Good Omens 8.1 Parks and Recreation 8.5
62 Seinfeld 8.1 Dragon Ball Z 8.4
63 Mr. Bean 8.1 Top Gear 8.4
64 Rome 8.0 Boardwalk Empire 8.4
65 The Office 8.0 The Punisher 8.4
66 A Discovery of Witches 8.0 Sacred Games 8.4
67 Chuck 8.0 Gravity Falls 8.4
68 TVF Pitchers 8.0 Supernatural 8.4
69 Orphan Black 8.0 Suits 8.4
70 Dekalog 8.0 Money Heist 8.4
71 Dr. Horrible's Sing-Along Blog 8.0 Mr. Robot 8.4
72 Fringe 8.0 Cosmos 8.4
73 The Vampire Diaries 8.0 Curb Your Enthusiasm 8.4
75 Star-Crossed 8.0 The Crown 8.4
77 Blackadder Goes Forth 8.0 Monty Python's Flying Circus 8.4
78 The Wire 8.0 Life 8.4
79 The Office 8.0 This Is Us 8.4
80 12 Monkeys 8.0 Big Little Lies 8.4
81 Timeless 8.0 Spartacus 8.4
82 Agent Carter 8.0 Hannibal 8.4
83 Justified 8.0 Futurama 8.4
84 How I Met Your Mother 8.0 Community 8.4
85 Once Upon a Time 8.0 The Newsroom 8.4
86 Gilmore Girls: A Year in the Life 8.0 Lost 8.3
87 Spartacus 8.0 Prison Break 8.3
88 House of Cards 8.0 Entourage 8.3
89 The Knick 8.0 The Shield 8.3
90 Longmire 8.0 Only Fools and Horses.... 8.3
91 Patrick Melrose 8.0 Star Trek: The Next Generation 8.3
92 24 8.0 Modern Family 8.3
93 The Americans 8.0 When They See Us 8.3
94 Glee 8.0 The Handmaid's Tale 8.3
95 Godless 7.9 Koombiyo 8.3
96 Arrested Development 7.9 Mindhunter 8.3
97 Downton Abbey 7.9 Dragon Ball Z 8.3
98 Travelers 7.9 Love, Death & Robots 8.3
99 Parks and Recreation 7.9 The IT Crowd 8.3
100 Broadchurch 7.9 Making a Murderer 8.3
101 American Crime 7.9 Justified 8.3
102 And Then There Were None 7.9 Spartacus: Gods of the Arena 8.3
103 Scream Queens 7.9 The West Wing 8.3
104 Jessica Jones 7.9 Scrubs 8.3
105 Battlestar Galactica 7.9 The Grand Tour 8.3
106 Over the Garden Wall 7.9 Fringe 8.3
107 Black Mirror 7.9 Luther 8.3
108 The IT Crowd 7.9 Blackadder Goes Forth 8.3
109 Grimm 7.9 Silicon Valley 8.3
110 Constantine 7.9 College Romance 8.3
111 The Other Sport 7.9 Taboo 8.3
112 Angel 7.9 The Night Of 8.3
113 The Killing 7.9 Blue Planet II 8.3
114 Beauty and the Beast 7.9 Friday Night Lights 8.3
115 The X-Files 7.9 The Walking Dead 8.3
116 The Exorcist 7.9 Adventure Time 8.3
117 Castle 7.9 Outlander 8.3
118 Utopia 7.9 24 8.3
119 The Young Pope 7.9 Bron/Broen 8.3
120 The Last Ship 7.9 Brooklyn Nine-Nine 8.3
121 Extras 7.9 How I Met Your Mother 8.3
122 Buffy the Vampire Slayer 7.9 Person of Interest 8.3
123 Smallville 7.9 Mr. Bean 8.3
124 Making a Murderer 7.8 The Office 8.3
125 The Pacific 7.8 Battlestar Galactica 8.3
126 Oz 7.8 The Legend of Korra 8.3
127 Six Feet Under 7.8 Chappelle's Show 8.3
128 Revenge 7.8 The Marvelous Mrs. Maisel 8.2
129 Olive Kitteridge 7.8 Sense8 8.2
130 Goosebumps 7.8 One Piece: Wan pîsu 8.2
131 Santa Clarita Diet 7.8 Fullmetal Alchemist 8.2
132 Da Vinci's Demons 7.8 Homeland 8.2
133 Entourage 7.8 BoJack Horseman 8.2
134 The Jinx: The Life and Deaths of Robert Durst 7.8 Louie 8.2
135 A Series of Unfortunate Events 7.8 Cobra Kai 8.2
136 Leverage 7.8 Flight of the Conchords 8.2
137 Limitless 7.8 American Crime Story 8.2
138 Blackadder II 7.8 The Blue Planet 8.2
139 Dirk Gently's Holistic Detective Agency 7.8 Californication 8.2
140 When Calls the Heart 7.8 Spaced 8.2
141 Blackadder the Third 7.8 Peep Show 8.2
142 Into the Badlands 7.8 Human Planet 8.2
143 Sherlock Holmes and Doctor Watson: The Acquaintance 7.8 The World at War 8.2
144 Are You Afraid of the Dark? 7.8 Flames 8.2
145 Generation Kill 7.8 The Big Bang Theory 8.2
146 TURN: Washington's Spies 7.8 Hunter x Hunter 8.2
147 The Fall 7.8 Ash vs Evil Dead 8.2
148 Almost Human 7.8 Yeh Meri Family 8.2
149 Furusato-Time 7.8 Generation Kill 8.2
150 Psych 7.8 Undercover 8.2
151 Counterpart 7.8 Stargate SG-1 8.2
152 Luke Cage 7.8 Psych 8.2
153 Nikita 7.8 Over the Garden Wall 8.2
154 The Playlist 7.8 Banshee 8.2
155 Vice Principals 7.8 The Mechanism 8.2
156 Pushing Daisies 7.8 The Americans 8.1
157 Rectify 7.8 The Jinx: The Life and Deaths of Robert Durst 8.1
158 The Mentalist 7.8 Code Geass: Lelouch of the Rebellion 8.1
159 Saved by the Bell 7.8 Steins;Gate 8.1
160 The Hollow Crown 7.8 Coupling 8.1
161 Dynasties 7.8 The Expanse 8.1
162 Scrubs 7.8 Atlanta 8.1
163 Our Planet 7.8 Dr. Horrible's Sing-Along Blog 8.1
164 Yeh Meri Family 7.8 Family Guy 8.1
165 Veep 7.8 White Collar 8.1
166 Louie 7.8 Sex Education 8.1
167 Horace and Pete 7.8 Black Books 8.1
168 Battlestar Galactica 7.8 Blackadder II 8.1
169 Cosmos 7.8 Ozark 8.1
170 The Act 7.8 The Originals 8.1
171 Spaced 7.8 Naruto: Shippûden 8.1
172 The Missing 7.8 Neon Genesis Evangelion 8.1
173 Sneaky Pete 7.8 Dragon Ball 8.1
174 The Strain 7.7 Our Planet 8.1
175 Years and Years 7.7 Blackadder the Third 8.1
176 Jericho 7.7 Justice League 8.1
177 Coupling 7.7 Frozen Planet 8.1
178 Marco Polo 7.7 Veronica Mars 8.1
179 Futurama 7.7 Orphan Black 8.1
180 Merlin 7.7 Das Boot 8.1
181 Dollhouse 7.7 The Killing 8.1
182 Hell on Wheels 7.7 Twin Peaks 8.1
183 Looking 7.7 The Pacific 8.1
184 Nathan for You 7.7 Samurai Champloo 8.1
185 Bron/Broen 7.7 Billions 8.1
186 Samurai Jack 7.7 Black Sails 8.1
187 The Gifted 7.7 Lucifer 8.1
188 Parenthood 7.7 The Last Kingdom 8.1
189 The Inbetweeners 7.7 Poirot 8.1
190 The Get Down 7.7 Dragon Ball 8.1
191 Flat TV 7.7 Father Ted 8.1
192 Wayward Pines 7.7 Dekalog 8.1
193 Humans 7.7 Young Justice 8.1
194 Who Is America? 7.7 Carnivàle 8.1
195 Flight of the Conchords 7.7 North & South 8.1
197 Waco 7.7 The Knick 8.1
198 Russian Doll 7.7 Pushing Daisies 8.1
199 The West Wing 7.7 Legion 8.1
200 Revolution 7.7 The Inbetweeners 8.1
201 The Adventures of Sherlock Holmes 7.7 After Life 8.1
202 Star Wars Rebels 7.7 Chuck 8.1
203 Breathe 7.7 Buffy the Vampire Slayer 8.1
204 Rules of Engagement 7.7 Whose Line Is It Anyway? 8.1
205 American Vandal 7.7 Ray Donovan 8.1
206 Halt and Catch Fire 7.7 Star Trek 8.1
207 Jesus of Nazareth 7.7 Kota Factory 8.1
208 Happy! 7.7 The Leftovers 8.1
209 The Defiant Ones 7.7 M*A*S*H 8.1
210 Escape at Dannemora 7.7 Blue Mountain State 8.0
211 The Lost Room 7.7 How to Get Away with Murder 8.0
212 John Adams 7.7 30 Rock 8.0
213 Vinyl 7.7 Altered Carbon 8.0
214 Sonic Boom 7.7 The Good Wife 8.0
215 Pretty Little Liars 7.7 Penny Dreadful 8.0
216 Colony 7.7 The Bugs Bunny Show 8.0
217 Only Fools and Horses.... 7.7 Orange Is the New Black 8.0
218 Pride and Prejudice 7.7 Impractical Jokers 8.0
219 The Shannara Chronicles 7.7 American Horror Story 8.0
220 The Tomorrow People 7.7 X-Men: The Animated Series 8.0
221 Generation War 7.7 Skam 8.0
222 Foyle's War 7.7 QI 8.0
223 Californication 7.7 Behzat Ç.: Bir Ankara Polisiyesi 8.0
224 Skam 7.7 The Daily Show 8.0
225 Wolf 7.7 Master of None 8.0
226 The Brave 7.7 Naruto 8.0
227 Atlantis Rising: The Making of 'Atlantis Down' 7.7 24: Live Another Day 8.0
228 Victoria 7.7 Gilmore Girls 8.0
229 White Collar 7.7 Bates Motel 8.0
230 Heroes 7.7 Gomorrah 8.0
231 Father Ted 7.7 Misfits 8.0
232 The Librarians 7.7 Boston Legal 8.0
233 Jonathan Strange & Mr Norrell 7.7 Samurai Jack 8.0
234 Banking Bad 7.7 The Blacklist 8.0
235 One Tree Hill 7.7 Fleabag 8.0
236 Chance 7.7 John Adams 8.0
237 Galavant 7.7 The Mentalist 8.0
238 House of Cards 7.7 Forever 8.0
239 Bloodline 7.7 The Colbert Report 8.0
240 Continuum 7.7 MythBusters 8.0
241 TVF Bachelors 7.7 Extras 8.0
242 Carnivàle 7.7 That '70s Show 8.0
243 Iron Fist 7.7 Criminal Minds 8.0
244 Monk 7.7 Eastbound & Down 8.0
245 Police Squad! 7.7 Killing Eve 8.0
246 Charmed 7.7 Castle 8.0
247 Steins;Gate 7.7 Utopia 8.0
248 Hatfields & McCoys 7.7 Skins 8.0
249 Black Books 7.7 Bodyguard 8.0
250 Deadly Class 7.7 Happy Valley 8.0

How does this compare to the original IMDb top 250 TV? Some general observations:

• Top shows on IMDb’s show-rating list generally appear near the top of my episode-rating list.
• Mini-series usually receive substantially lower episode ratings than show ratings. On the show-rating list, seven of the top 10 are mini-series (Chernobyl, Band of Brothers, Planet Earth, Cosmos, Blue Planet II, Our Planet), but only two make it onto the episode-rating list (Chernobyl and Les Synaudes).
• The episode-rating list lets some obscure shows sneak to the top. Vader: A Star Wars Theory Fan Series gets the #12 spot. My guess is that’s because it only has one episode, and because the demographic that watches the show is disproportionately likely to vote on IMDb. Perhaps we could correct for this by using an episode-weighting algorithm similar to the way we do vote-weighting, where the algorithm is more willing to give a show a high rating if it has a lot of episodes.

If we look at vote distributions, it appears that episodes are more vulnerable to vote stuffing than shows. Compare the vote distribution for Planet Earth versus the highest-rated single episode (“Pole to Pole”):

The show itself has 8.9% one-star reviews, but this episode has 22.6%. I find it difficult to believe that 22.6% of viewers hated the episode that much. More likely, some groups of people are trying to manipulate IMDb ratings by giving mass one-star reviews. And perhaps they try harder on episode ratings than on show ratings, or shows are harder to manipulate because they get more organic votes, or IMDb’s anti-vote stuffing algorithms are more effective for shows than for episodes.

## What if we used a lower vote minimum?

I originally used 1000 as the vote minimum because it’s a reasonable round number, and it looks fairly similar to how IMDb’s weighting works. But there’s an argument that 1000 is too high. Plenty of fairly popular shows have episodes with fewer than 1000 total votes–people on IMDb tend to rate movies and shows much more often than they rate single episodes.

There’s a tradeoff in deciding how strong our vote weighting should be. If we make the prior too strong by setting a high vote minimum, small but good shows get crowded out by popular shows that might not be as high-quality. But if we set too low a vote minimum, the top list becomes dominated by obscure shows that probably aren’t actually good.

We can look at how the top list changes when we reduce the vote minimum from one thousand to one hundred. For comparison, the left two columns show the shows and ratings with a 100-vote minimum, and the right two columns use the 1000-vote minimum that our previous list used.

Title (100-vote minimum) Rating Title (1000-vote minimum) Rating
1 Chernobyl 9.6 Chernobyl 9.6
2 Les Synaudes 9.4 Game of Thrones 8.8
3 Attack on Titan 9.2 Breaking Bad 8.8
4 BoOzy' OS 9.2 Daredevil 8.8
5 Vader: A Star Wars Theory Fan Series 9.0 Sherlock 8.8
6 When They See Us 9.0 Attack on Titan 8.8
7 Furusato-Time 9.0 Stranger Things 8.7
8 Daredevil 9.0 Les Synaudes 8.6
9 Code Black 9.0 The Leftovers 8.6
10 The Leftovers 8.9 Hannibal 8.6
11 Person of Interest 8.9 Person of Interest 8.5
13 Breaking Bad 8.9 When They See Us 8.5
14 Game of Thrones 8.9 True Detective 8.5
15 Hannibal 8.9 Sense8 8.5
16 One Punch Man 8.8 BoOzy' OS 8.5
17 The Originals 8.8 The Punisher 8.5
18 Parenthood 8.8 Band of Brothers 8.4
19 Doom Patrol 8.8 Lost 8.4
20 Sherlock 8.8 Narcos 8.4
22 Fawlty Towers 8.8 Firefly 8.4
23 24: Live Another Day 8.8 Dexter 8.3
24 Stranger Things 8.8 The Sopranos 8.3
25 Flat TV 8.8 Twin Peaks 8.3
26 Forever 8.7 One Punch Man 8.3
27 Star-Crossed 8.7 Fawlty Towers 8.3
28 Freaks and Geeks 8.7 Friends 8.2
29 American Crime 8.7 24: Live Another Day 8.2
30 The Punisher 8.7 Doom Patrol 8.2
31 Feud 8.7 Sons of Anarchy 8.2
32 Narcos 8.7 Code Black 8.2
33 Yeh Meri Family 8.7 Freaks and Geeks 8.2
34 Halka 8.7 House 8.2
35 Saved by the Bell 8.7 Banshee 8.2
36 Banking Bad 8.7 The Adventures of Sherlock Holmes and Dr. Watson 8.2
37 Teen Wolf 8.7 Black Sails 8.2
38 Banshee 8.7 Forever 8.2
39 Dr. Horrible's Sing-Along Blog 8.7 Penny Dreadful 8.2
40 Longmire 8.7 The Legend of Korra 8.2
41 Lost 8.7 Bodyguard 8.2
42 TVF Pitchers 8.7 Twin Peaks 8.2
43 12 Monkeys 8.7 The Originals 8.1
44 The Sopranos 8.6 Ash vs Evil Dead 8.1
45 TURN: Washington's Spies 8.6 Master of None 8.1
46 The Legend of Korra 8.6 Avatar: The Last Airbender 8.1
47 Blackadder Goes Forth 8.6 Bates Motel 8.1
48 Firefly 8.6 The OA 8.1
49 Black Sails 8.6 Gotham 8.1
50 Band of Brothers 8.6 Gravity Falls 8.1
51 Sonic Boom 8.6 Sharp Objects 8.1
52 Gravity Falls 8.6 11.22.63 8.1
53 True Detective 8.6 Boardwalk Empire 8.1
54 Playing It Straight 8.6 Teen Wolf 8.1
55 Sons of Anarchy 8.6 The Defenders 8.1
56 Dynasties 8.6 Feud 8.1
57 Fleabag 8.6 Luther 8.1
58 Bates Motel 8.6 Mad Men 8.1
59 When Calls the Heart 8.6 The Newsroom 8.1
60 Mr. Bean 8.6 Community 8.1
61 The High School 8.6 Good Omens 8.1
62 Dexter 8.6 Seinfeld 8.1
63 Ash vs Evil Dead 8.6 Mr. Bean 8.1
64 Avatar: The Last Airbender 8.6 Rome 8.0
65 Atlantis Rising: The Making of 'Atlantis Down' 8.6 The Office 8.0
66 The Playlist 8.6 A Discovery of Witches 8.0
67 Chuck 8.5 Chuck 8.0
68 Twin Peaks 8.5 TVF Pitchers 8.0
69 Cosmos 8.5 Orphan Black 8.0
70 The OA 8.5 Dekalog 8.0
71 Justified 8.5 Dr. Horrible's Sing-Along Blog 8.0
72 Beauty and the Beast 8.5 Fringe 8.0
73 A Discovery of Witches 8.5 The Vampire Diaries 8.0
74 The Newsroom 8.5 Fleabag 8.0
75 Wake Up Call 8.5 Star-Crossed 8.0
76 Master of None 8.5 Deadwood 8.0
77 The Office 8.5 Blackadder Goes Forth 8.0
78 Boardwalk Empire 8.5 The Wire 8.0
79 House 8.5 The Office 8.0
80 Orphan Black 8.5 12 Monkeys 8.0
81 The Other Sport 8.5 Timeless 8.0
82 Penny Dreadful 8.5 Agent Carter 8.0
83 The Knick 8.5 Justified 8.0
84 The Adventures of Sherlock Holmes and Dr. Watson 8.5 How I Met Your Mother 8.0
85 Deadwood 8.5 Once Upon a Time 8.0
86 Good Omens 8.5 Gilmore Girls: A Year in the Life 8.0
87 De Terugkeer van 8.5 Spartacus 8.0
88 Friends 8.5 House of Cards 8.0
89 Leverage 8.5 The Knick 8.0
90 Olive Kitteridge 8.5 Longmire 8.0
91 Battlestar Galactica 8.5 Patrick Melrose 8.0
92 The Vampire Diaries 8.5 24 8.0
93 Jesus of Nazareth 8.4 The Americans 8.0
94 Travelers 8.4 Glee 8.0
95 24 8.4 Godless 7.9
96 Gotham 8.4 Arrested Development 7.9
97 Rome 8.4 Downton Abbey 7.9
98 Mad Men 8.4 Travelers 7.9
99 Utopia 8.4 Parks and Recreation 7.9
101 Luther 8.4 American Crime 7.9
102 Rectify 8.4 And Then There Were None 7.9
103 Nikita 8.4 Scream Queens 7.9
104 The Defiant Ones 8.4 Jessica Jones 7.9
105 Rules of Engagement 8.4 Battlestar Galactica 7.9
106 Seinfeld 8.4 Over the Garden Wall 7.9
107 Over the Garden Wall 8.4 Black Mirror 7.9
108 Grimm 8.4 The IT Crowd 7.9
109 The Last Ship 8.4 Grimm 7.9
110 Timeless 8.4 Constantine 7.9
111 The Americans 8.4 The Other Sport 7.9
112 Patrick Melrose 8.4 Angel 7.9
113 Bodyguard 8.4 The Killing 7.9
114 Glee 8.4 Beauty and the Beast 7.9
115 Nathan for You 8.4 The X-Files 7.9
116 Scream Queens 8.4 The Exorcist 7.9
117 Horace and Pete 8.4 Castle 7.9
118 Wolf 8.4 Utopia 7.9
119 Breathe 8.4 The Young Pope 7.9
120 Once Upon a Time 8.4 The Last Ship 7.9
121 Twin Peaks 8.4 Extras 7.9
122 Sharp Objects 8.4 Buffy the Vampire Slayer 7.9
123 Oz 8.4 Smallville 7.9
124 Chance 8.4 Making a Murderer 7.8
125 TVF Bachelors 8.4 The Pacific 7.8
126 Revenge 8.4 Oz 7.8
127 One Tree Hill 8.4 Six Feet Under 7.8
128 Downton Abbey 8.4 Revenge 7.8
129 Vice Principals 8.4 Olive Kitteridge 7.8
130 11.22.63 8.4 Goosebumps 7.8
131 Community 8.4 Santa Clarita Diet 7.8
132 Generation Kill 8.4 Da Vinci's Demons 7.8
133 Looking 8.4 Entourage 7.8
134 Fringe 8.3 The Jinx: The Life and Deaths of Robert Durst 7.8
135 The Exorcist 8.3 A Series of Unfortunate Events 7.8
136 Pushing Daisies 8.3 Leverage 7.8
137 The Act 8.3 Limitless 7.8
138 The Living Planet 8.3 Blackadder II 7.8
139 Black and White Love 8.3 Dirk Gently's Holistic Detective Agency 7.8
140 Into the Badlands 8.3 When Calls the Heart 7.8
141 Coupling 8.3 Blackadder the Third 7.8
142 The World at War 8.3 Into the Badlands 7.8
143 Sneaky Pete 8.3 Sherlock Holmes and Doctor Watson: The Acquaintance 7.8
144 Blackadder the Third 8.3 Are You Afraid of the Dark? 7.8
145 Smallville 8.3 Generation Kill 7.8
146 The Killing 8.3 TURN: Washington's Spies 7.8
147 The Jinx: The Life and Deaths of Robert Durst 8.3 The Fall 7.8
148 Years and Years 8.3 Almost Human 7.8
149 And Then There Were None 8.3 Furusato-Time 7.8
150 Counterpart 8.3 Psych 7.8
151 Green Lantern: The Animated Series 8.3 Counterpart 7.8
152 SheZow 8.3 Luke Cage 7.8
153 Godless 8.3 Nikita 7.8
154 Blackadder II 8.3 The Playlist 7.8
155 Gilmore Girls: A Year in the Life 8.3 Vice Principals 7.8
157 The Missing 8.3 Rectify 7.8
158 Castle 8.3 The Mentalist 7.8
159 Are You Afraid of the Dark? 8.3 Saved by the Bell 7.8
160 Please Like Me 8.3 The Hollow Crown 7.8
161 The Norman Conquests 8.3 Dynasties 7.8
163 The Young Pope 8.3 Our Planet 7.8
164 Entourage 8.3 Yeh Meri Family 7.8
165 Extras 8.3 Veep 7.8
166 Ölene Kadar 8.3 Louie 7.8
167 Scenes from a Marriage 8.3 Horace and Pete 7.8
168 The Hunt 8.3 Battlestar Galactica 7.8
169 The Defenders 8.3 Cosmos 7.8
170 Hell on Wheels 8.3 The Act 7.8
171 Santa Clarita Diet 8.3 Spaced 7.8
172 Flames 8.3 The Missing 7.8
173 Waco 8.3 Sneaky Pete 7.8
174 Agent Carter 8.3 The Strain 7.7
175 Only Fools and Horses.... 8.3 Years and Years 7.7
176 House of Cards 8.3 Jericho 7.7
177 Making a Murderer 8.3 Coupling 7.7
178 Parks and Recreation 8.3 Marco Polo 7.7
179 Spaced 8.2 Futurama 7.7
180 Veep 8.2 Merlin 7.7
181 The Lost Room 8.2 Dollhouse 7.7
182 Violet Evergarden 8.2 Hell on Wheels 7.7
183 Samurai Jack 8.2 Looking 7.7
184 Little House on the Prairie 8.2 Nathan for You 7.7
185 Five Came Back 8.2 Bron/Broen 7.7
186 The Godfather Saga 8.2 Samurai Jack 7.7
187 Da Vinci's Demons 8.2 The Gifted 7.7
188 The Get Down 8.2 Parenthood 7.7
189 Psych 8.2 The Inbetweeners 7.7
190 Kingdom 8.2 The Get Down 7.7
191 Father Ted 8.2 Flat TV 7.7
192 Wayne 8.2 Wayward Pines 7.7
193 Arrested Development 8.2 Humans 7.7
194 College Romance 8.2 Who Is America? 7.7
195 Lonesome Dove 8.2 Flight of the Conchords 7.7
196 Dirk Gently's Holistic Detective Agency 8.2 Maniac 7.7
197 Flight of the Conchords 8.2 Waco 7.7
198 The Office 8.2 Russian Doll 7.7
199 Kevin (Probably) Saves the World 8.2 The West Wing 7.7
200 The New Edition Story 8.2 Revolution 7.7
201 Jonathan Strange & Mr Norrell 8.2 The Adventures of Sherlock Holmes 7.7
202 The Tomorrow People 8.2 Star Wars Rebels 7.7
203 Studio 60 on the Sunset Strip 8.2 Breathe 7.7
204 The Wire 8.2 Rules of Engagement 7.7
205 Scooby-Doo! Mystery Incorporated 8.2 American Vandal 7.7
206 Merlin 8.2 Halt and Catch Fire 7.7
207 Our Planet 8.2 Jesus of Nazareth 7.7
208 Battle Creek 8.2 Happy! 7.7
209 Constantine 8.2 The Defiant Ones 7.7
210 I, Claudius 8.2 Escape at Dannemora 7.7
211 Almost Human 8.2 The Lost Room 7.7
212 The Civil War 8.2 John Adams 7.7
213 Foyle's War 8.2 Vinyl 7.7
214 Grey's Anatomy: B-Team 8.2 Sonic Boom 7.7
215 Steins;Gate 0 8.2 Pretty Little Liars 7.7
216 The Brave 8.2 Colony 7.7
217 South Beach 8.2 Only Fools and Horses.... 7.7
218 Into the Universe with Stephen Hawking 8.2 Pride and Prejudice 7.7
219 Halt and Catch Fire 8.2 The Shannara Chronicles 7.7
220 Trailer Park Boys 8.2 The Tomorrow People 7.7
221 A Series of Unfortunate Events 8.2 Generation War 7.7
222 Louie 8.2 Foyle's War 7.7
223 Dekalog 8.2 Californication 7.7
224 Jericho 8.2 Skam 7.7
225 Skam 8.2 Wolf 7.7
226 Miranda 8.2 The Brave 7.7
227 Erased 8.2 Atlantis Rising: The Making of 'Atlantis Down' 7.7
228 Good Behavior 8.2 Victoria 7.7
229 The IT Crowd 8.2 White Collar 7.7
230 Galavant 8.2 Heroes 7.7
231 Çarpisma 8.2 Father Ted 7.7
232 John Adams 8.2 The Librarians 7.7
233 The Hollow Crown 8.2 Jonathan Strange & Mr Norrell 7.7
234 Daniel Sloss: Live Shows 8.2 Banking Bad 7.7
235 Limitless 8.2 One Tree Hill 7.7
236 Leyla and Mecnun 8.2 Chance 7.7
237 Happy! 8.2 Galavant 7.7
238 I Love Lucy 8.2 House of Cards 7.7
239 How I Met Your Mother 8.2 Bloodline 7.7
240 Six Feet Under 8.2 Continuum 7.7
241 Victoria 8.2 TVF Bachelors 7.7
242 Kuzgun 8.2 Carnivàle 7.7
243 The Mighty Boosh 8.2 Iron Fist 7.7
244 Bottom 8.2 Monk 7.7
245 The West Wing 8.2 Police Squad! 7.7
246 Whiskey Cavalier 8.2 Charmed 7.7
247 ReBoot 8.2 Steins;Gate 7.7
248 Pride and Prejudice 8.2 Hatfields & McCoys 7.7
249 Rescue 77 8.1 Black Books 7.7
250 Spartacus 8.1 Deadly Class 7.7

## Conclusion

Any rating system inevitably has bias. When people rate TV shows on IMDb, they might be rating how much they like the idea of the show more than how much they actually like the show, itself. They’re probably less likely to do this for individual episodes because it’s easier to rate an episode based on the actual experience you had watching it. On the other hand, the episode-based ranking appears vulnerable to vote stuffing. It also looks like people are much more likely to rate episodes that they love: for example, the top-rated episode of Attack on Titan has over 20,000 votes, but a typical episode only has about 2000. And both of these systems share a big source of bias: the ratings come from IMDb users, and IMDb users do not form a representative sample of the TV-watching population.

Given that every system has its own bias, I believe it’s valuable to look at different rankings, consider their differences, and think about how their biases may or may not reflect your own preferences so that you can find the rating system that’s the most helpful for you.

# Notes

1. In this particular case, the low ratings probably come from vote stuffing–the episodes have way more 1-star ratings than you’d naturally expect them to get.