comment: A bad decision that leaves Black with a difficult position.
context: 1. g2g4 In Freestyle, the initial position is already interesting and requires analysis. Perhaps the biggest peculiarity here is the placement of the king between the two rooks. As is usually the case, the moves that open the way for the bishop or the queen are the best ones. Here my favorites would be 1.f4, 1.g4, or 1.g3. 1... g7g6 A sensible move. Keeping the symmetry with 1...g5 looks weird, but it's also playable. 2. f2f4  2... d7d5 This pawn formation can give Black a headache, so it's worth thinking about an alternative here. 3. g1f3  3... e7e6 Preparing to develop the knight. 4. e2e3  4... b7b6  5. g4g5 Fixing the pawn structure, but White could also give priority to development. 5... e8d6  6. e1d3  6... h7h5 Before developing the knight, Sindarov decides to improve the structure on the kingside, avoiding being stuck with a fixed pawn on h7. He could also choose 6...h6. 7. d3e5  7... g8e7  8. b2b4 White's plan is to open the bishop's diagonal and fix the structure on the queenside with b4-b5. 8... e7f5  9. f1d3  9... f8e7 Both sides prepare \"short castling,\" or maybe I should say kingside castling since it's not so short here. 10. b4b5  10... c8d8  11. c1d1 There always comes a time when we have a \"normal\" position on the board, one in which the patterns are no longer as enigmatic as an exotic starting position with the king right between the two rooks, for example. This normality often appears after both sides have castled, arriving at a position that we can look at and, if no one told us, we might assume that it came from conventional chess. It wouldn't be impossible to imagine, looking at this position, that it had come from a Bird's Opening. 11... b8c8 Black wants to execute a break with c7-c6, activating his pieces. 12. f3d4  12... f5d4  13. d3d4  13... e7e8 Attacking the b5-pawn and preparing the pawn break again. 14. d4b4 Defending the pawn and preventing the break again. 14... d6f5 This allows White to play c4, although the position remains fine for Black. 15. c2c4  15... d5d4 A dynamic pawn sac that is totally justified. 16. h1a8 Landing a piece on c6 is the alternative, with both leading to equality: 16... c8a8  17. e3e4 Attacking the knight in order to capture the d4-pawn with the bishop.