Regarded as bad. Isolated doubled pawns are very nearly always bad. Temporarily doubled pawns not so much a problem, although there's that "temporarily" in there ... if they don't become un-doubled, well, then they're in the "probably bad" camp.
I'm sure someone can dredge up example positions where doubled pawns are a *good* thing, but in general I try to avoid them for myself and do try to inflict them on my opponents.
Don't forget that doubled pawns often control important squares and provide a open or semi open file for the rook to use. I think the weakness of doubled pawns is often severely overrated depending on the position.
Point, in the mid-game. Take away the rooks and have a couple of isolated pawn islands in the end game, and they're weak almost always. But yes, open and semi-open files are good, as is the extra ammunition for trading pawns in the centre and still having control there, if you have the right position for it. "Temporarily" still seems important to me; unless I'd elected to accept doubled pawns for a reason, I'd consider them a weakness in my position.
It's usually a weakness, but they shouldn't be looked at in isloation. You should consider what compensaton you have for them, such as semi-open files or extra control of central squares as others have said. I love it when an opponent plays their bishop to pin my knight, and then ends up taking it to mess up my pawns. I once played a game where they pinned and captured both of my knights. My pawn structure looked like crap, but I'll make that trade-off to get two bishops vs. two knights almost always.
Edit: just realized that this is the same topic creator who made the "why knights are better" thread, so chances are he agrees with 0% of what I wrote.
Double pawns are weak because they can be stopped by a single pawn and can't protect each other. Unless they can't be stopped by a single pawn (because it isn't there or can be taken) or unless they can be protected anyway by adjacent pawns, or...quite a few other ors. Also, as already pointed out, even if they are weak, it might be worth it if the opponent gives up a bishop for a knight, or if you get a nice open file to put a rook on. So...a slight situational weakness with many exceptions. In my opinion.
One of the benefits of doubled pawns is that two pawns are able to control four squares simultaneously. They are not really so good on the a and h files, but if you are able to double them up on the same b or g files, that allows for easy access and control of those files by your rooks. Especially if your opponent captures one of your knights or bishops on either the c or f files as it seems a lot of people like to bring their bishops out the fourth or fifth ranks to make idle threats against either the king or queen as though they are pinning their opponent's knight to those pieces. That style of tactic is alright for those who always like to play with early attacking aggression, but it gets old after seeing it time and time again. It is what it is though and really it all depends on the position you are in and seeing if you can get your opponent to fall on the blade end of their own "sword".
They are usually bad but sometimes good in certain positions
sometimes they are just awesome :P
Yea that's a pretty good example why doubled pawn can be good
Thanks Guy!
Thanks Guy!
Two things: thank you, and who says "Guy"?? lol
I don't like to have doubled pawns, because then the pawn can't guard the pawn to the front of it. I like to hear what you guys have to say though.