Best way to fight against players who play their f-pawn?

Hello, guys, how's it going?

Recently, I've been playing occassionally against this old man OTB and he's very aggressive old school style.

Anyway, I notice he plays f4 and f5 early; as white and black, respectively. He loves to play  Bird's opening, King's gambit, and the Grand Prix attack when I play the Sicilian.

Can you recommend some tips against this or how I may exploit an e4-f4 or e5-f5 pawn structure? Also, is it safe to castle kingside against such player? 

1) If your opponent is moving their 'f-pawn' on move number one (1 f4 for White and 1 ...f5 for Black), try to attack at the squares near their king.

2) Moving the 'f-pawn' means that the player wants his king to have an open diagonal once it castles kingside (maybe), so as White, keep your bishop on the a2-g8 diagonal and a7-g1 diagonal as Black to avoid kingside castle for as long as possible.

3) Its safe to castle kingside against such player, but make sure that when you castle, you have at least few pieces with the king (Queen, Rook, Bishop or Knight). If you may not do this, you may land yourself in trouble.

#1
The moves 1 f4 or 1...f5 do not develop any piece and weaken the later position of his king after his intended O-O as a diagonal is open that leads to his king.

The best method against the Dutch Defence is just steady development: d4, Nf3, g3, Bg2, O-O, c4, Nc3... Against the Bird opening just the same: ...d5, ...Nf6, ...g6, ...Bg7, ...O-O, ...c5, ...Nc6
By making useful developing moves you highlight the uselessness of the move ...f5 or f4.

The best response to the King's Gambit is to accept it: 1 e4 e5 2 f4 exf4. A pawn is a pawn. Black can hold the pawn and the pawn on f4 hinders the development of Bc1. Fischer was of the opinion that the King's Gambit loses by force
http://brooklyn64.com/wp-content/uploads/2015/11/a-bust-to-the-kings-gambit.pdf
AlphaZero and Kramnik later concurred.

Against the pure Grand Prix Attack 1 e4 c5 2 f4 d5 is most reliable.

Against the deferred Grand Prix Attack you can prepare ...d5: 1 e4 c5 2 Nc3 Nc6 3 f4 e6 4 Nf3 d5

Yes, of course you can and should castle O-O.

Yeah he did against Larry Evans on his journey to world champion.

From my experience I believe the best way to counterattacking e4 f4 / e5 f5 is stricking back on the center with e5 d5 / e4 d4

The game decided solely by those moves is called the falkbeer countergambit, which is a dangerous line for white and only worse than the more passive accepted variation (best move) for black by 0.2.

But even if those moves are thrown at different move orders, it seems that d4 / d5 to strike at the center pretty much always yields a great response

For instance, the grand prix attack is like 1e4, c5 2.Nc3 , and only then f4. Why not f4 on the second move? Theory says Nc3 needs to be played by white exactly to prevent d5 as a response.

On the Alexander gambit 1.e4, e5 2. Nf3, Nc6 3.Bb4 Bb5 4, c3, f5, the critical line is 4. d4, the refutation line.

The Duras gambit 1. e4, f5 is easily transposed into the stauton gambit with 2. d4 and suddenly white is the one on the attack

Thus, I always incorporate the d push on the center in order to counter the f push positions

Thank you so much, guys, these are great opening principles and ideas against those openings.

I'm glad you mentioned Fischer, because this guy absolutely loves him though I find it weird that he plays King's Gambit even though Fischer refuted it.

Anyway, I played him today and he didn't play his usual f4 (he tried c4) and I won.

@Shashank_Pali - Thank you for breaking down the idea for f-pawn push

@tygxc and @Karlabos - Thanks for pointing out its weakness, and how the d-pawn push is basically essential. I remember that I was losing to this guy because I'm reluctant to push my d-pawn because I fear that the game may become too sharp for my taste but I guess I need not to avoid it.

i used to fear these players who would launch these f pawn strikes agaisnt you.

But  you quickly learn in any given position, the pawn launch is not as scary as it looks.

1. quite often a focus on f4 /f5 leaves the opponent open to a nice counterstrike via d4/d5!. in fact, a lot of those f5 gambits in king pawn games of which most are dubious often have refutations involving d4 busting the whole center open. This is an example of the adage "best way to counter a wing-attack is a counterattack in the center"

2. a successful space grab on the kingside takes time. If the move is as scary as it looks you either got material compensation for it, have more space in the queenside and/or center or the push is really premature on your opponents end and is liable to be refuted usually by busting the whole thing open. If not, you already did something wrong beforehand. 

3.never underestimate potential for counterplay in the weak diagonals, quite often your opponent will need to move his king or do yet another preparatory move to not get punished. Especially powerful are knight+queen or bishop +knight pins and smoother mate threats.

#4
Yes, Fischer played a few King's Gambits, but never with 3 Nf3, always with 3 Bc4
https://www.chessgames.com/perl/chessgame?gid=1044288

https://www.chessgames.com/perl/chessgame?gid=1044179 

Thank you so much for this insight, really appreciate it from a titled player's perspective