First I want to say that I am a renowned hippo expert(what? you don't know me?It's your fault , not mine).I have played hippo many times in blitz in my chess club and have won with it even a NM(to be honest he lost because he almost fall from his chair from the laughs but that still counts as a win in my book).
Hippopotamus is not exactly an opening , it's a formation.The "hippoer"( I think I have heardthat word in a DVD about hippo but I'm not sure) develops within his own first 3 ranks at the beggining of the game.He will construct a solid, stable, yet flexible position,wait to see what white is doing and react accordingly but.........he must not wait too long.Poor timing will leave the "hippoer" horribly passive.
If you are going to play this "opening/formation" you need to know some things.
These are the basic "hippo principles"
1)You must have a good sense of humor.Occasional horrible defeats are inevitable
2)You must have a good sense of timing.Wait first for the centre pawns to be fixed, then hit them,
3)You must never hit first, always let your opponent come to you.
4)Don't wait too long, if your opponent delays , you are the one that must decide.
5)You must never let your opponent decide which files will open.You must decide that.
6)You must never let your opponent open the rook files*
7)You must never let your opponent exchange your bishops*
8)You must never castle before your opponent and always castle on the same side*
9)You must have patience, hippo is not for the impatient**
10)You must never despair , hippo is more resilient than it looks
*(unless you have a very good reason)
**(neither is chess)
I think you understood hippo's main disadvantages:
2)Surrender of the initiative to opponent for long which inevitably leads to.......
3)High percentage rate of finding yourself in a badly cramped, passive position waiting for the final blow.
But what are the advantages?
Sorry guys......there isn't any........
(Hippo principle No 1 , good humor needed)
Let's get serious, hippo is not to be underestimated, it's not exactly a nonsense(although very very close).In fact Spasky played it twice in his match for the World Championship at 1966 against the one and only Tigran Petrosian.It was impossible to play against Petrosian these days especially with black.Spassky used crazy lines to avoid Petrosian's superb opening preparation.Among the crazy choices he made, was also the hippo(twice!!!) which grant him 2 draws, not bad at all if you consider that he lost 3 games and won none with main lines and main openings(for the history , he lost the match but he won the title at 1969 using this time his superior preparation in Queen's Gambit declined and no hippo).Spassky never played hippo in an important game again but he started using it as a surprise weapon many years later(and many ranks under the 1st in the World Leaderboard).
Today no serious player uses it regularly and no serious player ever used it regularly but a lot are using it in blitz tournaments.One of them is World's No 10, Gata Kamsky who had considerable succeses with it.The main advantages of this opening are:
1)Easy to learn
3)No need to know opening principles(in fact , no need to know any kind of principles)
4)A lot of preplanned moves.
5)This is maybe the only opening system that never fully equalises and never really attempts to equalise.The real hippoer is always worst , slightly or more (even when he is winning).
The first 3 are self explained so let's talk about the last 2.
One of the great advantages for the blitz hippoer is that for a lot of moves are almost automatic.More than 80% of the cases your opponent's moves have specific correct answers which are the same in most of the cases.That means that only after a dozen of blitzes you will be able to play a lot of moves very quickly and still have a playable position.At blitz that is very important and makes hippo immediately a valuable weapon.
But maybe the most important advantage is that this opening never really equalises.That practically forces your opponent to prove he can do something with his advantage and that often backfires.Not few times you will face crazy attacks and irrational sacrifices and when you will face correct ones , your opponent will spend too much time to find them and he will lose from time(hopefully).
So let's see the basic hippo formation:
Often the precautionary a3 and h3(or ...a6 and ...h6 for Black) are added
Now let's see some rules that will help you survive.
The first one is:flank attacks.Your opponent most of the times will try to open one or both rook files by advancing the "a" or the "h" pawn.In both cases that must be prevented.
These 2 rook-file attacks is rare to occur both in a game as white has to decide where to castle too, so one side will probably stay as it is but in any case you must never allow your opponent a dangerous rook-file initiative and that is not only for the hippo.In all openings , when you face a similar attack you must consider the a6/h6 side-step as a possible antidote.
The a6/h6 sidestep(a3/h3 when you play as white) is also usefull when your opponent tries to exchange bishops.These early exchanges should be prevented.
But what happens if white castled short?This is a tricky situation as playing ...g5 is a whole different story.
Let's see a possible antidote:
The exchange of the other fianketo bishop is not the same story, because the queen can take it's place.
Let's see it:
That pretty much covers all the basic hippo principles except maybe the very important "first blood" principle.
Let's see an example game:
At the game that follows black is Vlastimil Hort, a Checz player born at 1944 climbing at No 8 of the World at 1977, and 6 times Checz Champion.He never played the hippo while he was on top 10 but obviously his opening preparation at 2002 was not at the level it was at 1977 and young players are "eating" opening lines for breakfast.
His opponent on the other side of the board is the young (12 years old) Holland Grandmaster Wouter Spoelman ,considered at 2002 as one of the greater talents in the world.
A classic battle , talent against experience.Spoelman is several points higher than Hort and most possibly he knows all cutting edge opening theory so everyone is betting on him.Has the "old man" any chance?