Hitconfirming apply to NG2/NGS2 too and is an important mechanic for people who want to play these games on Master Ninja difficulty. While on NG2 this mechanic is only used in a few spots because of the frantic nature of its gameplay which encourages the use of safe, single hit moves, in NGS2 it can be applied in many instances for no UT, no ninpo restricted play. And since many bosses or medium sized enemies can activate hyper armor, the player should check if his combos hit the target and stun it as well.
Here I'll post a few examples:
NG2/NGS2 Genshin fights, Dragon Sword: most Genshin attacks and combos can be punished with X, X, Y, ->Y (NG2, Xbox360) or Square, Square, Triangle, ->Triangle (NGS2, PS3). Though, the last two moves of the combo are not always safe because Genshin can dodge them by jumping away, and then punish with a fast dash attack. So, you should input the first two moves only and then check what happens:
1 - Genshin jumps away or doesn't get stunned (he uses hyper armor): you have to shuriken cancel, then immediately block. This way, you can block his attacks, and generally you can also block his dash attack and get guard broken. Sometimes though the dash attack will inflict damage even after the guard break, so if you see his dash attack you should try to dodge it.
2 - Genshin gets hit and stunned: you can perform the last two attacks in your combo, inflicting a considerable amount of damage.
NG2 (Xbox360) werewolf: in this game you generally use Falcon Talons ->Y or DCTF 360Y and you don't have to hitconfirm anything.
NGS2 (PS3) werewolf, DCTF: you can punish with T, T, T, T. Input the first two attacks, then check what happens:
1 - werewolf dodges or doesn't get stunned (he uses hyper armor): just block and you are completely safe from him (not from his complanions though, better trying to keep them off camera). If he is trying to do his shoulder ram, you have to dodge and even jump away if necessary, that attack is unblockable and kills Ryu in one hit regardless of how much HP he has.
2 - werewolf gets hit and stunned: do the last two inputs of the combo.
There are many other instances in which you should hit confirming and stun checking. In NG2 Xbox360 you should do it mostly against bosses, because normal enemies get easily delimbed with fast moves, while in NGS2 you should do it also against most medium sized enemies since they are harder to delmb. Most hit confirms start with two X or Square inputs, so do the first two attacks and if the enemy doesn't get stunned just block or dodge if he is doing an unblockable attack.