Source: Netflix

After more than a decade of flat or declining sales, chess sets are suddenly an in-demand item this holiday season, thanks to a fictional chess prodigy named Beth Harmon.

On Oct. 23, Netflix released the original limited series The Queen’s Gambit, which is based on a novel of the same name and follows Beth Harmon’s life and chess career.

Earlier this week, Netflix revealed that the show has become the most-watched limited series in the streaming platform’s history, with 62 million households watching in the first 28 days. In Netflix’s statement, Vice President of Original Series Peter Friedlander noted that Google searches for “how to play chess” had more than doubled, while Mary Higbe of Goliath Games told NPR that the company saw an exponential increase in demand for chess sets over the past month.

Source: The NPD Group

Now, The NPD Group has released data to show just how much The Queen’s Gambit has bolstered the market for this classic game. And the numbers are impressive: Sales for chess sets have increased by 87% in the three weeks following the show’s debut, while chess book sales rose by 603%.

“The idea that a streaming television series can have an impact on product sales is not a new one, but we are finally able to view it through the data,” Juli Lennett, toys industry advisor for NPD, said in an official press release. “The sales of chess books and chess sets, which had previously been flat or declining for years, turned sharply upward as the popular new series gained viewers.”