How to punish a early b5 in Ruy Lopez

Hi everyone. I have been playing the Ruy Lopez for a while and i have heard people claim an early b5 from black is bad. I know to push d4 if they play Nf6 but i struggle to keep the pressure up after exd4 and e5. Any suggestions?

yeah playing b5 as the openingmove might not be your best try but in the ruy lopez its the mainline to play b5 and its good.  do you have some spesific lines you have questions about?

I assume this is what is meant:

I am no Lopez expert, but I do not think that 4...b5 is considered good.

I think that there is some Archangel thingy where play includes 4...Nf6 5 0-0 b5.

I guess a4 will be the main challenge to it specifically. But it's not really a punishable move in terms of an outright refutation as far as I know.

I play the ...b5 idea as Black a lot. It doesn't matter if I begin with The Berlin (3...Nf6) or Morphy Defense (3...a6). Often times Black gets ...b5 in at some point, so it is not "punishable" by an immediate line that I am aware of, but Black does usually try to avoid this move too early. The reason why has to do with positional ideas. After 5.Bb3 (in post #3 by FrogCDE) take a look at Black's pawns. Black has a bit of a loose pawn structure on the Queenside: a6 is temporarily backwards, c7 is restricted from moving up at the moment and most importantly, the b5 pawn often becomes an early target for White to potentially aim at (especially if the a-pawn moves). 

GM Black players in this line choose to delay ...b5 as long as they can, so White can't yet attack these pawns, but Black usually gets in ...b5 a bit later anyway, so transpositions are common. I don't know of any direct line to refute an early ...b5, but positional-wise Black players simply prefer to avoid giving White any extra targets to hit. Strong Black players will usually opt for developing moves like ...Nf6 or ...Be7 until they absolutely need to play ...b5 - there are simply higher priorities such as piece development that come out first; but I don't know if ...b5 is intrinsically "bad" other than b5 being a potential target for White.

An early d4 in response introduces some interesting ideas that players who are playing an early b5 probably don't know.

In fact sometimes I just sac on f7 because I figure anyone bad enough to not know the standard Ruy move order can't beat me anyway.

But I've seen GMs just transpose into main line Ruys as white. In other words there's no special punishment for an early b5. It's just a normal game of chess (and my sacrificing on f7 is arrogant / stupid even though IIRC I've never lost while doing it )

Although, IIRC last time I looked, I think white saves time on not having playing Re1. Usually b5 comes after Re1 in the main line closed Ruys.

So it's like saving a fraction of a tempo

appreciate all the responses. Thank you.

Hey everyone!

Other thought about the risks of playing b5 by black:
-The queenside pawn structure is way to loose to allow a queenside castling. 
-White's light bishop aims directly at the f7 pawns, with a very strong position wether black choses to castle kingside or not. 

What do you guys think about this?