Mumbai, Nov. 19 -- Arjun Erigaisi's gaze shifted from the chess board to the ceiling. His glance moved across the grand hall of a posh Goan hotel, as he sat, calculating the next few possible moves, predicting his opponent's reaction, and the probability of a favourable outcome with a singular shift of a chess piece. On the board in front of him, he had a few options. Among those was his innocuously placed white bishop that could change the course of the game. Computer engines suggested that on the 24th move the bishop be moved from g2 to d5. The bishop would then - in all likelihood - be taken by the black queen immediately, but it would set Erigaisi on the path to a famous win in the quarter-final of the Chess World Cup, over Chinese Grandmaster Wei Yi. Erigaisi moved his arm to make a move, but then pulled it back down in a moment of hesitation. Once again he raised it. And then he made his move: queen from e2 to d2. "That's a very human move," Tania Sachdev, a member of the Indian team that won gold at the Chess Olympiad last year, said during ChessBase India's commentary. In a sport that likens its sharpest players to computers - sometimes even beating those computers - world No.6 Erigaisi showed a more human touch. In the moves that followed, both players continued to strategise on the board until Erigaisi made his 32nd move. As he shifted his rook to d2, the Indian whispered a "draw offer." Almost immediately, Wei accepted. The result now takes the tie into the Rapid-style tiebreakers on Wednesday after both their classical matches ended in draws. It could have all been different if Erigaisi had moved the bishop, but it was an extremely difficult spot in the best of times. But he had enough time to study the position. One needs to harken back to the Indian's previous round win over two-time Chess World Cup winner Levon Aronian to know the devastation one wrong move can make. For 79 moves across two classical format matches, Aronian made the right calls. On the 80th, he made an error. The Indian spotted it and ended the match by moving his knight. It was not beyond Erigaisi, the second seed and India No.1, to have spotted the benefits of moving the bishop on Tuesday. But this was a match in which both players were under pressure and this is what over-the-board chess can sometimes do to you. Wei, especially after he took over 35 minutes to make his 20th move, was tight on time too. He then blundered with 21...Nd7 but despite that, the Chinese GM - who is undefeated in the classical chess format in his five World Cup appearances - was not playing passive chess. And at times, Erigaisi, once dubbed the 'Mad Man of Chess' by Magnus Carlsen for his attacking and fearless style of play, was on the defensive. To his credit though, the Warangal native found the right moves at the right time to stay out of danger. What added to the pressure was the fact that both players - the highest ranked competitors still active in the World Cup - are now within touching distance of a spot in next year's Candidates Tournament. Erigaisi missed out on qualifying for the event where the winner plays in the World Championship match. He has talked about how the miss took a toll on him, and that he had to take a 20-day break to recover. Once he did get back though, he became one of the best players in the world. But facing him in the quarter-final is Yi, the seventh seed and world No.11. After the match on Tuesday, Yi immediately pointed to the white bishop to let Erigaisi know there was a chance for the match to have ended with a result. The two GMs discussed the matter for a few more minutes before parting ways. Erigaisi however, is not one to dwell on a missed chance for too long. "All these top guys, they are super practical about this," Sachdev said. "(They know) that from an engine it's easy to find (the perfect move), but from a human perspective, (they'll say) 'I didn't see it, it didn't happen, end of story.' I don't think they keep thinking about it and beating themselves over (about what I missed)."...