An open intending traping opponent's knight.

This is how I will make my move to trap a knight when ur opponent fall into this position, combining with the Advanced Open. Take a look at 3

 diagrams below. But rarely ur opponent make moves like this, and somehow ur opponent could play Nb4, and then back to the safety 6th rank at Na6. Sometimes, ur opponent could miscalculated (usually with the advanced players), or wanted to risk, especially medium or easy lever players, they think they would support their knight by the pawn in e5, or perhaps I could think they don't want to retreat back and rather stay somewhere, I think. Anyway, I named my own figured technique "Mate Knight" .....

Yep, Nd4?? is a blunder, Ne7 (or perhaps Nb8) is called for.