Rounds four to six of the rapid tournament at the Tata Steel Chess India event were played on Thursday, completing the second day of action in Kolkata. With the final three rapid rounds scheduled for Friday, the rapid champions in both sections will be decided before the tournament continues at the weekend with blitz double round-robins.
In the open section, the Indian pair of Viswanathan Anand (56) and Nihal Sarin (21) share the lead on 4½/6. Wesley So follows in sole third place with 4/6, while Arjun Erigaisi, Praggnanandhaa Rameshbabu and former co-leader Hans Niemann are grouped on 3½/6. That trio trails the leaders by a full point but remains within striking distance going into the final day of the rapid section.
Anand and Niemann began Thursday tied for first place, but both suffered defeats in round four. As a result, there are no longer any undefeated players in the open tournament. With four of the five games ending decisively in that round, the standings compressed dramatically, producing a six-player group at the top.
In round five, out of the six co-leaders, only Anand, Nihal and So managed to score wins, leaving the three tied for first place heading into the final round of the day. Importantly, Anand defeated Niemann, dealing a significant blow to the American's title hopes and leaving him a full point behind the leading group.

Vishy Anand defeated Hans Niemann with the black pieces | Photo: Vivek Sohani
Round six proved pivotal. Anand, a five-time world champion in classical chess, completed the day with his second consecutive victory, a notable recovery after his round-four loss. Nihal also won in round six, thus ending the day level with Anand at the top of the standings.
Nihal’s performance on Thursday marked a sharp turnaround from his opening day. After Wednesday's play, he stood on a fifty-percent score, having won one game and lost one. On day two, the 21-year-old won all three of his games, defeating Niemann, Volodar Murzin and Vidit Gujrathi. His run in Kolkata follows a solid showing at the recent World Rapid Championship in Doha, where he entered as the 24th seed and finished 19th with a commendable 8½/13 score.
One of the most discussed moments of the day came in So's round-six game against Praggnanandhaa. The game ended in a draw after an unusual incident in the final position, when Pragg stopped the clock with a second remaining because he could not immediately find a queen to promote a pawn.
So may have been entitled to claim a win under the regulations, but instead the game was agreed drawn. Afterwards, So explained that his opponent had intended to promote but panicked when no queen was available nearby and stopped the clock to call the arbiter. He added that he preferred to win games on the board rather than through technical claims.

Arbiters apparently consulting Wesley So, who chose not to take advantage of an unexpected circumstance which could have cost his opponent the game | Photo. Vivek Sohani

Hans Niemann | Photo: Vivek Sohani
As on the opening day, the women's tournament concluded Thursday's play with a sole leader, in contrast to the shared lead in the open. Kateryna Lagno collected two wins and a draw to move to the top of the standings, and is now the only player in Kolkata, open or women's, to remain undefeated after six rounds.
Lagno's wins both came with the black pieces, against reigning women's world rapid champion Aleksandra Goryachkina and Stavroula Tsolakidou. Her strong showing follows a consistent performance in last year's edition of the tournament, where she finished fourth in the rapid event before going on to win the blitz section.

Kateryna Lagno | Photo: Vivek Sohani
Carissa Yip, who started the day as the tournament leader, dropped back to sole second place. Yip opened Thursday with a draw, then lost to Nana Dzagnidze, before recovering with a win over Vantika Agrawal. She now trails Lagno by half a point.
Dzagnidze occupies sole third place, a half point behind Yip.
Looking ahead to Friday's decisive rounds, the frontrunners face differing schedules: Lagno and Dzagnidze, who drew their encounter in the first round, will each have two games with the white pieces, while Yip will play one game with white and two with black. Yip is set to meet Lagno with the white pieces in round eight, a pairing that is likely to play a key role in determining the winner of the women's rapid tournament.

Carissa Yip | Photo: Vivek Sohani

Nana Dzagnidze | Photo: Vivek Sohani
Annotations by GM Karsten Müller