Because the Botez sisters mention it in the description of a YouTube video. With BotezLive, they have more than 1 million subscribers. They educate and entertain the 'new' chess players.

Chess used to be a game dominated by grumpy old males, spearheaded by a charismatic and sexy world champion from Norway. It has turned into a game for everyone. The new players start watching on TikTok, Twitch, and YouTube. They play on, our new parent company. And eventually, some of them will enter a tournament, find a club, and buy a chess book.

In the video, Andrea Botez shows the difference between a Chess Amateur and a Professional with the help of Woman Grandmaster Dina Belenkay. Dina uses an exercise from 'the book about strategy every Russian kid has studied', called Techniques of Positional Play, by Valeri Bronznik and Anatoli Terekhin, published in English by New In Chess.

PS: New In Chess has three other titles in the Kindle top-10, all well suited to adult improvers:

  1. 1001 Chess Exercises for Beginners (all Elo categories)
  2. 100 Endgames You Must Know (1000 Elo plus)
  3. How To Study Chess on Your Own (1500 Elo plus).