A Korean title's run at home leans the odds abroad. It does not decide them, and format decides more.

Anyone selling a Korean show abroad has heard the same shorthand: it did well at home, so it will travel. Anyone buying has heard it too. It is a testable claim, and Netflix publishes enough to test it — a weekly top 10 for 93 markets, including Korea’s own.

We took the 915 Korean titles that appear on any of those lists between 2021-07-04 and 2026-07-26, counted how many places each took on Korea’s chart, and asked how far it went afterwards.

The home run does lean the odds

A title with one or two weeks at home reached ten countries about one time in nine. A title with six to ten weeks did it more than half the time. That is a real difference and it is worth knowing.

It is a slope, not a door

The first version of this piece said threshold. It was wrong, and the way it was wrong is worth showing, because it is the most common way a table like this gets misread.

The median number of foreign countries per title goes 1 → 19 between the 3–5 band and the 6–10 band. That looks like a door swinging open at six weeks. But the median only records where the middle title sits; when a group crosses from “most titles go nowhere” to “most titles go somewhere”, the median leaps while the underlying distribution barely changes pace. The share reaching ten countries tells the honest version: 11.4% → 25.5% → 56.5% → 63.2%. Nothing snaps. It leans.

And format leans harder

Series stay on charts longer than films nearly everywhere, so a band cut on run length might be sorting formats under another name. We split every band rather than argue about it.

Both effects are real, and the format effect is the bigger one. In the 3–5 band a series reached ten countries 52.3% of the time against 8.0% for a film — a wider gap than the entire home-chart range for films. A film that ran six weeks in Korea travelled less often than a series that ran three. If you are going to read one column, read the format.

We also checked whether long home runs simply belong to older titles, which would make this a story about the calendar. They do not: the median first week is 2023-06-04 for the 1–2 band, 2023-12-03 for 3–5 and 2024-04-07 for 6–10. The band that travels most is the newest of the three.

The home chart is not a gate

29 titles reached twenty or more countries without ever appearing on Korea’s own top 10.

These are not marginal abroad. Oasis held a top 10 place in 82 different countries. It is simply absent from the list at home — which is a fact about Korea’s chart, not about the title. Korea’s own top 10 is crowded with titles that never leave, and a show can be squeezed out of it while doing perfectly well elsewhere.

The comparison we did not make

Of the 915 titles, 560 charted in Korea and 355 never did. The obvious move is to put those two groups side by side and report which travels further. We did not, and the reason is worth stating rather than burying: the 378 are in our data only by virtue of having charted somewhere abroad. A title that charted in neither place is invisible to us entirely. Comparing the two groups would answer a question we had already decided by the way we built the list.

So the bands above are cut inside the 560 that did chart at home, where the comparison is honest, and the 378 appear only in the section above — as named cases, not as an average.

What a seller can take from this

The home run is a prior, not a filter. Six weeks at home roughly quintuples the odds of reaching ten countries against one or two weeks — but a fifth of the titles in that band still never leave, and thirty titles cleared twenty countries with no home run at all. Any process that uses the domestic chart as a gate is discarding titles that travel.

Every figure here is on the table behind this piece, band by band, with the films and series columns left in: the home-and-abroad table. The per-market picture — how much of each country’s chart Korean titles take, and how many different titles that is — sits at catalogue depth, where every one of the 93 markets now has its own page.

What this does not say: that these titles are good, or that anyone watched them. A top 10 is a rank list. It records what held a place against the other titles in that country that week, and nothing else.