1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8f6  4. d2d3  4... f8c5  5. b5c6  5... d7c6  6. b1d2  6... f6d7  7. e1g1  7... e8g8  8. d2c4  8... f8e8  9. g1h1 [%c_effect h1;square;h1;type;Interesting;persistent;true] Not a very popular move, but it was played in two important games in 2022 by Ukrainian GM Kirill Shevchenko. GMs Viswanathan Anand and Fabiano Caruana, among others, have also tried this move in older games. The main idea of the mystery king move is to prepare the f-pawn advance and also vacate the g1-square for the white knight, which can maneuver via g1-e2-g3, as will happen in the game. Of course, it's hard to believe that this plan gives White an objective advantage, but what is sought in this line is a middlegame position that allows for the creation of imbalance. 9... b7b6 A theoretical novelty. The move is natural, as the pawn on b6 is useful to reinforce the structure after the c6-c5 move, something that will inevitably happen sooner or later. Furthermore, the bishop can be developed on b7 in some cases. 10. f3g1 Kosteniuk sticks to the expected plan. 10... d7f8 Continuing the dance with the knights. 11. g1e2  11... f8g6  12. e2g3 White gives up the f4 break. 12... c8e6  13. c4e3  13... f7f6  14. g3f5 This move is the beginning of White's problems, as it won't be easy to execute a promising plan after this. It seems correct to take the other knight to f5: in that case, White could transfer the queen to g4 and then play h4-h5. It's always nice when we know what our next moves will be in an ideal world. 14... d8d7 