What does the boy’s glance most likely make Anvi realise?

Read the passage and answer the questions given below it.

The fan above Board Three clicked on every turn, as if it were keeping score. Anvi had stopped hearing it an hour ago. Now she could hear nothing else.

Fourteen minutes on her clock, nine on his. The boy from Satara had a steel tumbler of water at his elbow that he had not touched since the opening. He had not looked up since move thirty either.

A draw would be enough. Sir had said so in the bus, twice, tapping the seat in front of him. “Half a point and you are in the state team. Don’t try anything clever.” She could see the draw clearly: queens off the board, pawns locked, a tame handshake over two scoresheets. It was safe. It was also how she had played all season, and she knew it.

The other move had come to her a minute ago, and it would not go away. Knight to f5. To the parents pressed against the glass door, it would look like a piece thrown away for nothing. To her it looked like a door left open. If she had read it right, his king had nowhere to hide in six moves. If she had read it wrong, she would be explaining it to Sir all the way home.

She picked up her pen and wrote nothing. Outside, her mother was holding the tiffin box in both hands, as though it might spill.

The boy shifted, glanced at the clock, and then, for the first time, at her. His face was calm. He was waiting for the queen trade. Everyone was.

That decided it. Anvi laid the pen down beside the scoresheet and reached for the knight.