Aggressive Defence - Ivanchuk's technique and a local example by IM Kevin Goh
In Ivanchuk: Move by Move (Everyman, 2015), I noted that the title - Aggressive Defence - can be used to describe Ivanchuk’s way of warding off attacks as he "does not conform to patient, passive defence where solid barricades are set up, inviting the opponents to overreach or run out of gas, in the hope of exploiting the weaknesses left behind. He tends towards the counter-attack, continuing to gain space and push for the initiative, even with his king in mortal danger. By so doing, Ivanchuk challenges his opponents to out-calculate him, often along a narrow and steep path where highly accurate moves are required. The risks are great, with double-edged complications aplenty, but so are the rewards".
One example that I used in the quiz section was the following game.
As you can see, Ivanchuk counter-punches vigorously as even as his opponents start to aim for his king, even at the risk of putting his own king in danger and usually succeeds in the tactical melees that follow.
Interestingly, I just came across a parallel local example demonstrated by IM Goh Wei Ming this morning. Playing White vs FM Ong Chong Ghee in a training game, the following position was reached.
Ghee had just pushed ...g5-g4 in an attempt to burn White down the g-file. Now, the logical thing to do for White here would be to take on g4 and hunker down. White will thus endeavour to avoid getting mated while advancing his own cause on the queenside or centre. This seems to be a no-brainer right? But watch what happens from here!
Note that while Wei Ming is training hard for a final push at the GM title (one norm to go) with another European stint in the coming months, Ghee is training for a half marathon instead, which probably explains the ...f6?? boo-boo and how this exciting fight got terminated so abruptly.
Lastly, if you trust your engines, you would say that hey, Black didn't defend optimally and with correct play, he should be better after 16 Ne5. However, don't forget that humans can't defend like engines and blunders are there, waiting to be made, especially in such a high-octane position.