TV ratings are numbers inherent in almost every K-drama. You might have ignored them all the time but they play a significant role for the broadcasters and the people who worked on the show. After all, they are a measure of how small or large the audience is for a particular series, and thus they provide a way to determine whether drama X is a success or failure as far as viewership (and popularity) is concerned.

In this post series titled HIGHEST RATED 2018, we will be presenting Korean drama rankings related to TV ratings. Our aim in publishing this content is for you to know which are the top Korean dramas in 2018, ratings-wise (assuming that viewership is a very useful indicator of popularity, i.e. there exists a positive correlation between TV ratings and popularity).

In addition to rankings, we have key rating statistics that you will never find elsewhere. What is the average rating of all cable dramas last year? Which genre and TV network recorded the highest average rating? And, more importantly, how did terrestrial and cable K-dramas performed relative to each other? We used a method to rank all the series last year, notwithstanding the palpable difference in ratings between terrestrial dramas and their cable counterparts.

Here is the table of contents for the first part of this post series:

Rankings by Average Ratings (Top 10 Average)

In the terrestrial TV category, last year’s top Korean drama in terms of average TV ratings is Return, whose broadcast is marked by a controversy in the middle of production. Go Hyun-jung stepped down as the lead actress because of a large dispute between her and the producing director. If you were expecting the ratings to drop because of that mess, think again. During the week when her departure from the show was officially announced, Return achieved its peak rating and sustained an impressive double-digit viewership until the finale. In the end, it obtained an average rating of 13.7%, the highest among all terrestrial TV dramas.

The Miracle We Met gets the silver prize with an average rating of 10.9% while Should We Kiss First rounds out the top 3 with 9.5 %. Another noteworthy drama which made it to the top 10 is Suits, the Korean remake of the American TV series of the same title.

In the said category, the top Korean dramas in 2018 have an average rating of 9.0%, which is lower than its 2017 and 2016 counterparts—13.0% and 16.3%, respectively. We are seeing a downward trend here. In fact, the average rating of all terrestrial dramas in 2018 fell by 32% year-on-year. But that is not the case for cable dramas.

Mr. Sunshine is the record-holder in the cable TV category, having an impressive average rating of 13.0%. This figure is the highest average rating of a cable K-drama of all time, beating Goblin’s 12.9% and Reply 1988‘s 12.4%. Interestingly, both Mr. Sunshine and Goblin were written by Kim Eun-sook and directed by Lee Eung-bok (in case you missed it, they also worked together to produce Descendants of the Sun). Surely, expectations of success are sky-high in their next projects.

In second place is the blockbuster satire Sky Castle, which started off with below-2% viewership but went on to obtain an average of 12.5 % and became the 3rd highest-rated (in terms of average) cable K-drama in history. The bronze medal goes to 100 Days My Prince which secured an average of 9.0%.

We should congratulate Misty and Sky Castle for making it to the list despite their relatively unpopular leads—Kim Nam-joo and Yum Jung-ah, respectively. Kim and Yum pale into significance when compared with Lee Byung-hun (Mr. Sunshine), D.O. (100 Days My Prince), Song Hye-kyo and Park Bo-gum (Encounter), Hyun Bin and Park Shin-hye (Memories of the Alhambra), Park Seo-joon and Park Min-young (What’s Wrong With Secretary Kim), Ji Sung (Familiar Wife), Lee Joon-gi (Lawless Lawyer), and Lee Kwang-soo (Live). These two dramas prove that a series with a superb screenplay can win the hearts of viewers even if it has no famous leads.

The top Korean dramas in this category boasts an average of 8.4%. This is higher than the 5.4% and 5.9% recorded by their counterparts in 2017 and 2016, respectively. Overall, we are seeing a 41% increase in average ratings of all cable dramas last year relative to 2017.

Rankings by First Episode Ratings (Top 10 Premiere)

The first episode is important in that it has the ability to make or break a hit drama. In 2018, the record-holder in the terrestrial TV category is The Miracle We Met, which premiered with 8.2% and went on to end its broadcast with the second highest average rating. Seven other dramas in this list also started with relatively high ratings and made it to the Top 10 Average.

In 2017, the record-holder is Saimdang, Light’s Diary. Starring in the series is Lee Young-ae, the female lead in the mega-hit sageuk Jewel In The Palace.

In cable TV, it is quite obvious that dramas headlined by very popular stars and penned by renowned screenwriters easily made it to the top 10. Starring in the record-holder Mr. Sunshine is Lee Byung-hun. And who would forget that it’s a Kim Eun-sook drama? Meanwhile, the lead actors in Encounter and Memories of the Alhambra are A-list celebrities. In Hwayugi‘s case, the writers are the Hong sisters. 7 out of 10 dramas found in the list below made it to the Top 10 Average.

While Return has a spot both in the Top 10 Average and the Top 10 Premiere, Sky Castle is nowhere to be found here as it is in the Bottom 5 Premiere.

In 2017, Prison Playbook is the first placer thanks to the PD who helmed it—Shin Won-ho of the Answer Me/Reply series.

Rankings by Final Episode Ratings (Top 10 Finale)

Return is again on top in the terrestrial TV category with 16.7%, followed by The Miracle We Met and Thirty But Seventeen. We should expect the dramas in the Top 10 Average to dominate this ranking as well, and they all did minus Bad Detective, which is in the 13th place. It is replaced by Investigation Couple, which is in the Top 15 Average.

Defendant is the title-holder in 2017.

Meanwhile, in cable TV category, Sky Castle ended its broadcast with almost 24%, multiplying its first episode rating by about 14 times. That’s like having just one family watching its first episode, but during the finale, an entire city was tuning in. Totally impressive.

Woman of Dignity boasts the highest-rated finale in 2017.

Rankings by Peak Ratings (Top 10 Peak)

Some fans prefer the peak ratings-based ranking to the average ratings-based list, so we have created the Top 10 Peak as well. This is last but definitely not the least since the media oftentimes refer to peak ratings when comparing the viewership of two dramas.

In terrestrial TV, Return is no. 1 and all but one drama in the Top 10 Average are occupying this list. Investigation Couple came 10th, replacing Heart Surgeons which settles for 12th place. No terrestrial drama last year surpassed 20% in viewership, which partly explains why the overall average ratings of such shows decreased year-on-year.

In 2017, Defendant held the highest record.

The proud winner in the cable TV category is Sky Castle. Not only did it surpass 20% during its finale, but it also solidified its status as the cable drama with the highest-rated episode in Korean TV history. Interestingly, second placer Mr. Sunshine and third placer 100 Days My Prince are also in the Top 5 Peak of all time, along with Reply 1988 and Goblin.

Woman of Dignity also recorded the highest peak rating in 2017.

Ranking Roundup

Highest Average Rating in Terrestrial TV: Return (SBS)

Highest First Episode Rating in Terrestrial TV: The Miracle We Met (KBS2)

Highest Final Episode Rating in Terrestrial TV: Return (SBS)

Highest Peak Rating in Terrestrial TV: Return (SBS)

Highest Average Rating in Cable TV: Mr. Sunshine (tvN)

Highest First Episode Rating in Cable TV: Mr. Sunshine (tvN)

Highest Final Episode Rating in Cable TV: Sky Castle (JTBC)

Highest Peak Rating in Cable TV: Sky Castle (JTBC)

In the second part of this post series, we published a ranking of all 2018 dramas in relative terms.

Some Notes on Methodology

Analysis. Before anything else, we compiled and verified all the rating information we needed and recorded them in a spreadsheet. We then analyzed the data using Pivot Tables.

Rank. Dramas with high ratings rank higher than those with small ratings.

Drama. A total of 70 dramas (33 on terrestrial TV, 37 on cable TV) were included in the ranking. They are the major primetime dramas (MPDs) known locally and abroad. Each of these shows meets the following criteria:

It is a primetime terrestrial TV drama airing every Mondays & Tuesdays or Wednesdays & Thursdays on KBS2, MBC, or SBS OR a primetime cable TV drama airing every Mondays & Tuesdays, Wednesdays & Thursdays, Fridays & Saturdays, or Saturdays & Sundays on JTBC, OCN, or tvN. (Daily dramas and weekend family dramas are not included.)

Its Nielsen TV ratings are available online.

It aired at least 50% of its total no. of episodes in 2018.

It was not included in the previous year’s ranking.

Network. Each of the terrestrial TV networks is represented by 11 dramas. Meanwhile, tvN, JTBC, and OCN are represented by 18, 11, and 8 dramas, respectively. These networks are the top 6 biggest broadcasters of Korean dramas in South Korea.

Ratings. Rating values are nationwide audience shares measured by Nielsen Korea and are expressed in percentage.

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