1. Harika Dronavalli just had to mate with knight+bishop against Tan Zhongyi to survive for the tiebreak, since Tan had won the first classical game. She did wobble a lot and only managed to get potential mate on move 163 (Tan resigned on move 162), when Tan would be able to claim a draw on move 167! Apparently she did not know the W-maneuver with the knight via b3-d4-b5-d6-b7 but had a less efficient maneuver involving Bg6.

Harika, Dronavalli vs Tan, Zhongyi

 PGN Viewer

One remarkable thing is that after 56.Be4!,f5 she did not see the mate after the simple 57.Qe7+,Kxc8 58.Bd3 followed by Ba6(+) and Qb7# checkmate.

One thing I always wondered about the Deletang triangle, it will still not avoid that the opposing King can run back to the wrong corner and stay there, from which only the W-maneuver will work to extract it?

2. Originally Posted by Jesper Norgaard
Harika Dronavalli just had to mate with knight+bishop against Tan Zhongyi to survive for the tiebreak, since Tan had won the first classical game. She did wobble a lot and only managed to get potential mate on move 163 (Tan resigned on move 162), when Tan would be able to claim a draw on move 167! Apparently she did not know the W-maneuver with the knight via b3-d4-b5-d6-b7 but had a less efficient maneuver involving Bg6.

Harika, Dronavalli vs Tan, Zhongyi

 PGN Viewer

One remarkable thing is that after 56.Be4!,f5 she did not see the mate after the simple 57.Qe7+,Kxc8 58.Bd3 followed by Ba6(+) and Qb7# checkmate.
True! I guess she might have settled down for the grind a P ahead and didn't consider a sac to mate quickly

Originally Posted by Jesper Norgaard
One thing I always wondered about the Deletang triangle, it will still not avoid that the opposing King can run back to the wrong corner and stay there, from which only the W-maneuver will work to extract it?
I think you are supposed to form the triangle around the enemy K and the right corner, and it seems possible to keep him there.

3. Originally Posted by Capablanca-Fan
I think you are supposed to form the triangle around the enemy K and the right corner, and it seems possible to keep him there.
That is true in many starting positions. It wasn't in Harika's game, and if the king actually occupies one of the wrong corner squares, Deletang will not help at all!? Which means you need to learn the W-maneuver as well as Deletang. That may be fine since Deletang is general-purpose and will be possible in 70-80% of starting positions. But if you refuse to learn the W-maneuver, you will be in for a shock in 20-30% of the starting positions if the opponent plays to stay in the wrong corner no matter what.