Oranguttan-Polish

The opening is largely based upon tactics on the queenside or the f6- and g7-squares. Black can respond in a variety of ways: For example, Black can make a claim on the centre (which White's first move ignores) with 1...d5 (possibly followed by 2.Bb2 Qd6, attacking b4 and supporting ...e7–e5),^[6] 1...e5 or 1...f5. Less ambitious moves like 1...Nf6, 1...c6 (called the Outflank Variation, preparing ...Qb6 or ...a5), and 1...e6 are also reasonable. Rarer attempts have been made with 1...a5 or 1...c5. Black's reply 1...e6 is usually followed by ...d5, ...Nf6 and an eventual ...c5. After 1.b4 e5 it is normal for White to ignore the attack on the b-pawn and play 2.Bb2, when 2...d6, 2...f6, and 2...Bxb4 are all playable. After 1...a5 White will most likely play 2.b5 and take advantage of Black's queenside weakness. Black's 1...c5 is much sharper and more aggressive and is normally used to avoid theory. After the capture Black will generally place pressure on the c5-square and will develop an attack against White's weak queenside structure at the cost of an inferior central position.

1.b4 has served me well as my primary chess opening from 1200 to 2200 (now). my first GM scalp in OTB play came from 1.b4 (or rather it would have, i botched a completely winning ending into a draw

the opening is actually rather positional instead of tactical (The main exception being the 1.e5 2.bxb2 lines). where white gets's lasting space advantage on the queenside which is usually favourable in the ending. If black plays too passively, white can sometimes get an avalanche of pawns going. white castles kingside basically in almost all lines, but in some lines its preferable to delay castling, especially if white ends up in a pawn storm race where black storms the kingside.

the main disadvantage is that its a little slow for a white opening, especially the bxb4 lines where the main line with 4.c4, white must be REAL careful not to fall even one tempo down . it also reveals your intention a little too soon in the opening and allows black to choose almost any system in response.

the polish is a sound opening that leads to unsusual equal to slightly += positions for white depending on the black response. another thing is that all the so called refutations from black are really bluff. 

Yeah, it's unwise to play 1. ..e5 against.  A reply I haven't seen posted yet is 1. ..c6, which an Expert I know uses to good effect.  This opening was a mainstay of a C-rank player in my local club, who understood the opening very well (he never beat me with it, but I always had to work very hard to get out of the opening OK).

The main goal of the opening is to gain space on the queenside and fianchetto that bishop to attack on the long diagonal.  For black, getting the queenside pieces developed becomes an immediate imperative, but you also have to block the long diagonal before you castle.  There are a lot of sound replies to 1. b4, mind you, but it create urgent tasks for black which must be attended to right away, and which aren't trivial to accomplish.

As one that has played it over the board roughly 250 to 300 times as White and 3 times as Black, I highly beg to differ with your ignorant statement that it is "unwise to play 1...e5".

1...e5 is Black's STRONGEST response!  It is the only move that, when followed up correct, gets Black full equality.  The fact that Black can get full equality out of the opening with 1...e5 is the exact reason why you never see this played at the GM level.  After moves like 1.e4, 1.d4, 1.Nf3, or 1.c4, if both sides play the absolute best moves, White gets a tiny (I emphasize, tiny) advantage.  With 1.b4, White gets no advantage after 1...e5 2.Bb2 (2.a3 is no better) Bxb4 3.Bxe5 Nf6 and now 4.Nf3 and 5.e3 leads to passive play for White and Black should grab the center.  After the more dynamic 4.c4 (the line I play), then 4...O-O 5.Nf3 (or 5.e3) Re8!.  Do not be tempted by the early ...Nc6 lines.

Against inferior lines like 1...d5 or 1...c6 2.Bb2 Qb6 3.a3 a5 4.c4 axb4 5.c5! Qc7 6.axb4 Rxa1 7.Bxa1, White has the same slight advantage that he gets when he plays 1.d4 or 1.e4.

These "inferior" lines by no means lose for Black, and are "ok" to play, but if Black wants the best possible position he can get after 1.b4 and achieve full equality, then 1...e5! is the answer.

1...e5 is THE REASON why 1.b4 is not my primary opening.  I still play it occasionally, even in regular time control, over the board tournament competition, but 1.d4 is my primary line of play as White with an occasional 1.b4, 1.Nf3, or 1.e4.

I certainly have not played it as many times as you offensively, but I have had to defend it numerous times against opponents up to the Expert level.  Your analysis seems reasonable, however, along the 1. ..e5 line the fourth move I usually see (and play) is 4. g3.  Why?  Because black can't build a stable center without his e-pawn, and he'll have to commit to a clumsy defense of the b-pawn.  Of course, the open b-file will eventually have a white rook on it, so the other fianchetto will coordinate well with it.

Most folks don't play white in the hypermodern style, but the Orangutan is a hypermodern opening, and needs to be treated as such.  Controlling the center doesn't have to mean occupying it.  In that context, 1. ..e5 enables a hypermodern approach to the opening.  In other words, white doesn't need to change his plan, and that's usually good for white.

Of course, my local club is unusual in that the hypermodern style, and aggressive tactical play in general, is favored over more classical approaches.  When we play as black, we go for counterplay, not necessarily equality.

The other responses, 1. ..c6 and 1. ..Nf6 (which is what I usually play) are not as passive as you might think.  The c6 move is a prophylaxis against 2. b5 (which can be played immediately and to good effect against 1. ..e5), which can be really troublesome for queenside development.  With 1. ..Nf6, you can proceed with 2. ..d6 which baits the exchange (again, planning to use the open file so the doubled f-pawns are OK) and 3. ..e5 if the exchange is declined, rendering the b2 bishop ineffective.  In both cases, black's queenside knight is destined for d7 instead of c6, which makes the queenside space disadvantage far less meaningful.

i fully concur that 1.e5 is the only real line that gives black full equality. in fact, playing 1.b4 e5 2.bb2 bxb4 against a strong prepared tactical player is a very scary experience. 4.c4 is the best response but black gets a lead in development that requires care (although 4.c3 might actually lead to new unique positions from the bit i explored with it.

i am also in full agreement that the early nc6 lines are harmless, as nc6 does nothing to stop the eventual d4. once white gets d4 rolling (and especially without a knight on d5 which often can be sacrificed on e3 if a rook ins on e8 with unclear positions) white already has a slight advantage.

The vain of white's existence is if black gets d5 and c5 bc then white must settle for one of two choices, either an easily blockable D4 isolani or a two to one pawn island on the queenside if it reaches an ending. This is why 4.c4 is so important. i have tried 4.nf3 5.g3 and 4.e3 5.nf3 6.be2 but in both lines you give black a tiny advantage if he plays right.

for that reason against 1.b4 e5 2.bb2 bxb4 3.bxe5 nf6 4.c4 0-0 5. e3 d5 6.nf3 c5 6.cxd5 nxd5 7.qc2 is essential. the reason is that if possible, white should play a3 and qxc5 or at least if a knight is on c6 threaten d4 without black being able to take d4. the two pawn island with c and a pawn is favorable for white instead of the a and b pawn island. the second reason is that white should play the anti-intuitive bd3 in these lines where white can often get a small attack going with ng5 or be4. third, qc2 supports nc3 to exchange off the annoying nd5 knight which as mentioned before threatens nxe3 and nf4 detours after 0-0. white should NEVER allow black to trade twice on c3 and have to take with the d pawn. goes back to the unfavorable pawn island problem.

another small annoyance is that they are certain tricky move orders in the e5 bxb4 lines, and they are often easy to miss if you want to play the first 10 moves automatic as many 1.b4 club players do.for example 1.b4 e5 2.bb2 bxb4 3.bxe5 nf6 4.c4 0-0 5. e3 d5 6.nf3 re8 7.bb2 bf5!? looks like your average development move but in fact threatens c5 without the qc2 antidote! white ought to play precisely 8.a3 and if bd6 9.d4 is best or if ba5 9.cxd5 nxd5 10.qb3 is best forcing black to not play c5.

you can also experiment with 1.b4 e5 2.a3 which is not bad and in fact the extra tempo from the st george defense gives white many interesting possibilities otherwise not possible for example 

e3 is more thematic and might even be better but e4 is just fascinating here. early c4 here actually severely limits black's play since c5! is a very real threat and c6, allows cxd5 nc3 and nb5. for this reason 3.nd7 is black's best bet.

i also had a miniature agaisnt an expert player  OTB who got a little too confident in the 1.c6 antidote.

and poor black is a pawn down. my opponent resigned in moral shame even though he prob should have played on. thing is older players are only familiar with 4.c4 axb4 5.c5! but this bd4 alternative is fairly recent. nf3 looked like white decided to gambit the pawn.

The Expert I knew who used the 1. ..c6 defense usually followed with 2. ..d5 - the objective is to get the queen's bishop out, then that knight to d7, followed by the pawn thrust to e6 or e5.  The move Qb6 makes little sense unless the e-pawn has moved and white's bishop has been blocked in its attack on g7.  Why bring the queen out when you have nothing else to coordinate it with?

Again, if black focuses on queenside development, and thwarting the long diagonal, the c-pawn just stays on c6.  The point is to prevent white from playing b5.

very tricky opening, 1...e5 is the best move without a doubt- requires a lot of study

OK, all of you touting 1. ..e5 - I've already raised my objections, and none of you seem to be answering the lines I've proposed.  You can't count on opponents playing inferior continuations, you have to account for all possibilities before you can call a particular response "best".

I've never seen a player who knew what they were doing try any of the 1. ..e5 continuations you've shown here, and certain moves within them seem like glaring errors to me.  This makes me question how thoroughly you've examined the issue.

1.e5 is only dangerous if black plays in a specific way. a lot of players play 1.e5 simply for fast easy development, which it does allow.

the london system formation is fine for black but i believe white should keep a small advantage bc of the extra space.

this line may not seem that dangerous at first, but in truth white is calling all the shots here with the greater mobility and space of the queenside and center pawn structure. black has good development but he doesnt call much of the shots. he can play dxc4 but this only helps white. i have always done very well with this line. 

here is a near win from me agaisnt IM bartholomeow agaisnt the london style set up. very instructive game although i botched it in time pressure.

https://www.youtube.com/watch?v=RZpRqubWjYA

Didn't read every post but I think it's worth noting that the main trump of 1. b4 is that it usually leads to odd positions that the majority of players are both unfamiliar with and uncomfortable playing. Therefore, if you're comfortable playing it, you'll already have a psychological advantage over your opponent. It can lead to very sharp play, both tactically and positionally. Study some games by Sokolsky. He was a great exponent of the opening and played some remarkable games using it as an effective weapon against very strong opposition