Top Kdramas in 2018 In Terms of TV Ratings: Terrestrial Versus Cable

In the second part of this post series called HIGHEST RATED 2018, we will first look at how the terrestrial and cable dramas generally performed in terms of TV ratings. If you’d like to see immediately the top 10 K-dramas in 2018 in relative terms, just scroll down until you see the first item of the list. But I highly recommend that you read the first paragraphs for some interesting K-drama ratings statistics.

If you haven’t read the first part of this post series, click here. It has the absolute rankings of 2018 Korean dramas in terms of average and peak TV ratings.

Take note that our analyses for the following reports are only concerned with the average nationwide ratings (from Nielsen Korea) of the series.


In the terrestrial TV category, the mean of the average ratings (=overall average rating) stands at 5.6%. Out of the 33 terrestrial dramas last year, 18 or 54.5% have average ratings lower than this number. The figure closest to this value is 5.5% and recorded by the KBS sci-fi romance drama Are You Human Too?.

The median average rating is 4.8%, which belongs to the short SBS melodrama Exit. In other words, half (16) of the total terrestrial dramas have average ratings smaller than 4.8% while the other half have average ratings higher than this number.

The standard deviation of the average ratings is 2.8% and the range is 11.5%.

Meanwhile, the cable dramas obtained an overall average rating of 4.8% (closest to this value is Life‘s 4.7%), just less than 1 percentage point lower than its terrestrial counterpart. This record is quite something; in 2017, the difference stood at almost 5 percentage points since the terrestrial dramas had an overall average of 8.2% while their cable counterparts got 3.4%. In 2016, the gap is even higher, at 6 percentage points.

23 (or 62.2%) out of the 37 cable dramas have average ratings smaller than the overall average.

The median average rating is equal to 4.3%, which was recorded by My ID Is Gangnam Beauty. Meanwhile, the standard deviation and range are equal to 2.8% and 11.9%, respectively.

Average Ratings of 2018 Cable K-dramas


I would like to introduce a term called the relative viewership performance (RVP), which is simply a grade or category assigned to a drama that describes how good or bad it performed (ratings-wise) relative to the overall performance of the group it belongs to (terrestrial or cable TV). It is determined by the standardized value of the average rating, or by how far from the overall average a drama’s average rating is in terms of standard deviation.

These are the 7 RVP grades and their corresponding standardized value and average ratings.

Estimated Range of Average Ratings of the 7 RVP Grades for the Year 2018

According to this, 28 or 40.0% of the total dramas in 2018 have an average RVP and only 3 (or 4.3 %) obtained an excellent RVP. Meanwhile, 22.9% of the total are above-average, with the terrestrial and cable groups contributing 50% each.

Relative Viewership Performance (RVP) of 2018 K-dramas

We will release all the findings of our report this week, so make sure to come back here if you are interested in the information.

That’s it for the intro. Here is the relative ranking of 2018 Korean dramas:

11. TERIUS BEHIND ME (RVP: Good) — 1.04

Terius Behind Me is MBC’s no. 1 drama based on average ratings and the only representative of the network to this top 11 ranking. It’s a spy comedy starring So Ji-sub as a black ops agent working for the National Intelligence Service who teams up with his widowed neighbor (Jung In-sun) to uncover the truth behind her husband’s involvement in a huge conspiracy. The only MBC drama with an above-average RVP, its success can be attributed to the popularity of actor So who is best known for his roles in Oh My Venus and Master’s Sun.

10. SUITS (RVP: Good) — 1.20

The folks at KBS2 are happy knowing that this Korean remake of the US TV series of the same title was a success as far as TV ratings are concerned. Jang Dong-gun is starring in the drama as an A-list lawyer who hired a genius, played by Park Hyung-sik, to become his associate lawyer. They two make up a formidable duo but the problem is, the genius guy doesn’t really have a law degree and the lawyer recruits him despite knowing his real background. Out of the seven dramas last year that are remakes of a foreign TV series, Suits is the best-performing (ratings-wise) and the only one with an above-average RVP. It was helmed by Kim Jin-woo, the director of Healer and Good Doctor.


Thirty But Seventeen a rom-com headlined by Yang Se-jong and Shin Hye-sun, directed by Jo Soo-won (I Can Hear Your Voice), and penned by Jo Sung-hee (She Was Pretty). Yang took on the role of a set designer who falls in love with a woman (Shin) suffering from a decade-long coma and waking up thirteen years later with a “mental age” of a 17-year-old. But she’s actually 30 years old during her recovery, thus the title. The series is the best-performing romantic comedy in 2018 and is one of the only two rom-coms with an above-average RVP. That is no ordinary feat, especially when you consider the fact that rom-coms make up 14.3% of the total no. of series last year, the highest percentage among the 25 different genres.


Memories of the Alhambra is one example of a show with a very unusual and interesting (aka unfamiliar) concept that is brought to life by A-list lead actors under the leadership of a writer (W-Two Worlds) and director (Secret Forest) with solid credentials. Hyun Bin played an investment company CEO who goes on a business trip abroad to meet the creator of an innovative augmented reality AR game. There, he gets the first-hand experience of the game, discovers how promising it really is, and eventually buys it from the creator’s sister (played by Park Shin-hye). But things take a sinister turn as he finds himself getting entangled in strange events when the border between the real world and the fictional world of the game begins to collapse.

7. ENCOUNTER (RVP: Good) — 1.33

This is Song Hye-kyo‘s comeback drama following her 2016 romantic series Descendants of the Sun (DOTS). Encounter didn’t end up like DOTS which surpassed 30% in ratings but it did achieve this record last year: the most successful Korean drama under the romance & romantic-comedy genres. It’s all thanks to Song and his co-star Park Bo-gum‘s status as very well-known actors who can actually deliver a badass performance. The series centers on a hotel CEO (Song) who has everything she needs, except for her freedom to do the things that really makes her happy. When she travels abroad for an official business trip, it’s business as usual for her until she meets the ordinary and free-spirited young man (Park) who will change her life forever. The series comes from the director of Jealousy Incarnate.

6. SHOULD WE KISS FIRST (RVP: Good) — 1.41

Should We Kiss First is an unexpected success, having achieved a double-digit viewership during its first week and almost sustained such record until the finale. It’s a romantic melodrama starring Kam Woo-sung and Kim Sun-ah as two adults who have lost their faith in love but are both afraid of living and dying alone, ending up finding true love in each other. Kam and Kim won the Grand Prize in the 26th SBS Drama Awards for their performance. The series is the third best-performing drama in 2018 under the melodrama and satire genres.

5. 100 DAYS MY PRINCE (RVP: Very Good) — 1.52

This drama showed right off the bat that it would pull off a very successful broadcast, which is characterized by a peak rating of 14.4%. D.O. played a prince who wakes up a beggar with no memories of the past, especially about his status as the crown prince of Joseon. Then he meets a commoner with whom he is forced to tie the knot, in accordance with a law he himself created. His wife, played by Nam Ji-hyun, lashes out at him because he can’t do even the simplest household chores. It’s cute—their interaction and all—but what happens when he regains his memory? There are only 3 historical dramas last year and it’s good to see the two of them making it to this list.

4. THE MIRACLE WE MET (RVP: Very Good) — 1.91

Fourth placer The Miracle We Met is the best-performing melodrama in 2018. It stars Kim Myung-min as a father and husband who finds himself living two identities when he dies due to a car accident and wakes up inside the body of another man. Kim Hyun-joo and Ra Mi-ran play his original and new wife, respectively. Given that synopsis, here’s another record The Miracle We Met can be proud of: the most successful 2018 Korean drama with a fantasy/supernatural element in its story.

3. SKY CASTLE (RVP: Excellent) — 2.78

I’m glad to announce that the bronze medalist is the blockbuster satire Sky Castle. The lone representative of JTBC to this list, Sky Castle is the biggest sleeper hit of 2018. It recorded only 1.7% on its premiere but went on to achieve 23.8% when it ended. When we’re going to talk about how well a show’s viewership has improved since its first episode, it is the clear winner, with a whopping 22 percentage points-increase or 1300%. Wow. The series stars Yum Jung-ah as a mother desperate to make her daughter enter the country’s most prestigious medical school. She’s not alone, because all the other moms in her exclusive and luxurious neighborhood (with the same name as the drama’s title) are also obsessed with making sure that their kids end up studying in the best university. The topic is socially relevant as it is about Korea’s overly competitive education system.

2. RETURN (RVP: Excellent) — 2.89

SBS’s highest-rated Korean drama in 2018 settles for second place. Return is the best-performing series under the sci-fi, mystery, action, and thriller drama cluster, which makes up 30% of the total no. of series last year. Go Hyun-jung played the female lead character, a lawyer who takes a murder case involving South Korea’s powerful elites and ends up realizing (along with a detective portrayed by Lee Jin-wook) that there’s a lot more to the case than meets the eye. However, from the 16th episode, Park Jin-hee took over as the heroine, following an official announcement saying that Go stepped down as the lead actress because of a dispute she had with the producing director. What a mess. There was real drama happening behind the scenes. The hard work of the production team still paid off though. And that’s the thing that matters the most.

1. MR. SUNSHINE (RVP: Excellent) — 2.94

The gold medal goes to Mr. Sunshine, the most successful Korean drama in 2018 relative to the overall viewership performance of its group. The historical series follows the life of a Korean man, played by Lee Byung-hun, who was taken to the U.S. as a child and returns to his homeland as an American Marine Corps officer. It’s a critically acclaimed drama that received 9 nominations in this year’s Baeksang Arts Awards, including Best Drama, Director, and Screenwriter. With Sky Castle also boasting the same number of nominations, the no. of awards each of them will receive will determine which between the two is the winner when it comes to popularity and quality. In case you missed it, this is the third drama directed by Lee Eung-bok and written by Kim Eun-seok, the director-writer pair behind DOTS and Goblin.


What is this standardized value again? In simplest terms, it’s a number that represents how far from the overall average the drama’s average rating is in terms of standard deviation (if you’re also unfamiliar with this term, Google can help). It can be positive or negative; when it’s positive, it means the drama’s average rating is above the overall average and when it’s negative, the average rating is lower than the overall average.

So why are we having this ranking? It is wrong to compare cable dramas with terrestrial dramas using their actual average ratings because the former group tend to get lower ratings than the latter, i.e. cable drama X with a 3% rating is not necessarily doing poorly when compared with terrestrial drama Y with a 6% rating. Here’s an analogy, as a senior you get a final average grade of 88% in your science high school while your friend who is studying in a regular high school obtains 79%. While it’s true that you do have a higher grade (in absolute terms) compared with her, you can’t say that you did better than her because the two schools follow different curricula and ways of grading students. One way to better compare your performance with your friend is to determine how well each of you performed relative to the overall performance of your respective classes. Similarly, that’s basically what we are doing to answer this question: are terrestrial dramas doing better (ratings-wise) than their cable counterparts?

I’ll end this post by showing you the following numbers:


Mean Rating: 5.6%
Median Rating: 4.8%
Standard Deviation: 2.8%
No. of Dramas with above-average RVP: 24.2%
No. of Dramas with average rating higher than the overall average: 45.5%


Mean Rating: 4.8%
Median Rating: 4.3%
Standard Deviation: 2.8%
No. of Dramas with above-average RVP: 21.6%
No. of Dramas with average rating higher than the overall average: 37.8%

So, which group did better? You be the judge.


InternJang manages a team of writers to publish and promote content for Kdramapal every day. He began watching Korean dramas in 2014 and fell in love deeply with his all-time favorites Signal, Reply 1988, and Misaeng. His affinity for writing led him to start a blog and, later on, spearhead efforts to establish KDP as one of the most dependable sources of K-drama information online.

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