Grob opening(How to punish it)
So if u don't know Grob opening. It was been listed on one of the worst openings to play. Yet alot of people don't know theory.
This is Grob opening ( for White)
Grob opening is weak because u don't play for the center. The h4 square may be weak.
If u are black here are the basic theory of the Grob!
Let's anylise the most played move ever.
So we have the variation Bg2 which it's called the Grob gambit:
There are hundreds of games played c6 as black but I recommend to take the g4 pawn which is the 2nd most popular move.

White will play c4 which is the most popular move. The point of sacrificing the pawn from White pieces are to exploit the b7 pawn. The b7 pawn is weakened because our bishop has leave the diagonal.
The next moves will be shown on the board.
People will get scared at this position but ur okay. Play Nd7.
There are people will be greedy take our c6 pawn thinking that they get a good position with 1 pawn up.
If they play Qa4 we play Rxc4 and the only way to save the game is to go back to d1.
As u can see our rook is developed. Our bishop is developed. Our knight is developed. The Only piece in white position is active is Bishop on G2. Well the bishop is kinda useless. Is a completely winning position and if u don't blunder while playing I have faith in you that u can win the game.
Now if they don't play Qa4 but play any safe Queen moves we can still take on c4 and our position is still great and white King's castle to King side maybe dangerous now.
So if u want to be safe u can play 2. C6

Both moves have significant winning chances according to Masters databases.
Hope u guys have a good chess!
Facts: Alot of people lost to Grob because they don't know theory. Don't be like them : )