Herman Grooten: Key concepts of Chess – The Hedgehog - A review

by ChessBase
10/26/2023 – The "hedgehog" structure is a very resistant structure that also offers many possibilities for active play. It is not the specific variations that are important, but the knowledge of the typical ideas and plans. Dutch coach Herman Grooten teaches this in his Fritztrainer course "Key concepts of Chess - The Hedgehog". Philipp Hillebrand had a look at the course.

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By Philipp Hillebrand

Key concepts of Chess – The Hedgehog, a Fritztrainer by IM Herman Grooten

Some time ago I wrote a review of Yannick Pelletier's Fritztrainer about the Hedgehog. In his new course on the Hedgehog Herman Grooten does not want to present big theoretical innovations, but he wants to explain the ideas of the Hedgehog-structure, and his vast experience in communicating ideas and concepts is immediately apparent. Although Grooten may not be as well known as Pelletier, he is in no way inferior to him when it comes to conveying ideas, plans, strategies and tactics that can be understood by less experienced chess players thanks to the way they are didactically presented.

This Fritztrainer is very structured, moving from individual elements of a strategic or tactical nature to a discussion of games that the author has played. I think this is absolutely justified, as playing the hedgehog contains many psychological elements, and an author can discuss these much more authentically if he has played these games himself. So the "summary" is as follows:

I. Introduction

II. Learning from the Hedgehog Classics

III. Typical Plans for White

IV. Typical Plans for Black

V. The Marozcy Bind in relationship to the Hedgehog

VI. Games of the author

VII. Exercises

About I.

The author provides schematic plans and background knowledge, discussing the diagrams at this point with only the relevant pieces and, of course, the pawns:

The structure of the black pawns is what gives the "Hedgehog" its name, as Black's pawns control the center and the queenside on the fifth rank, making it very difficult for White to establish an outpost there. Especially, square d5 is one that both sides aim to fully utilize. The white pawns on e4 and c4 keep a close watch on this strategically important square, also aiming to keep the backward black pawn on d6 under control.

However, the Hedgehog possesses some unique dynamics, and from my own experience, both with the white and black pieces, I know that the more pressure you apply to these pawns, the fiercer the counterattacks tend to be, especially when the breakthrough ...d6-d5 occurs, unleashing the power of the black pieces. Therefore, it's not uncommon to employ the lever ...b6-b5 to weaken the d5 square. Consequently, the player with the white pieces must always consider three possible levers: the move ...b6-b5, the move ...d6-d5, or a combination of both.

This realization alone leads you to expect tactics. And White cannot simply wait to enjoy its spatial advantage, for when the Hedgehog unfurls its spines, it can become very painful for White. Space is also tricky in the Hedgehog. It is a misconception to believe that Black is worse because Black's pieces seem to lack space. In fact, Black's pieces can be very effective, even when standing on the back rank:

This position comes from the game Wintzer, J - Grooten, H, 0-1 (47), Lugano 1989. Black's last move was 47...Qb6-b8!, after which White resigned.

The diagram position illustrates many elements of the Hedgehog, as White can often make significant progress on the queenside, but on the other hand has to take care of his king, particularly when queens are still on the board and White pushes his f-pawn. Therefore, Black should usually avoid to exchange queens, despite Black's spatial disadvantage. The more pieces leave the board, the more vulnerable the black d6 pawn becomes, and the spatial disadvantage can then become more pronounced. Hence, Black should seek his chances in a king-side attack, and that's what the Hedgehog player desires – a wild king hunt!

About II:

In a TV game (with a time control of 60 minutes) played between the future World Champion Robert Fischer and the emerging Swedish talent Ulf Andersson, an Hedgehog position emerged on the board, albeit with colors reversed:

Here, it is White who has a Hedgehog structure and here Fischer played 13.Kh1!!, a move with attacking purposes as White wants to follow up with Rg1 and g2-g4-g5. Fischer won the game with logical and energetic play, inspiring pioneers like GM Adorjan, GM Ribli, and especially GM Suba, to take a closer look at the Hedgehog. They played very instructive and aesthetically pleasing games with this structure, and it's worth exploring these classics.

Unfortunately, they are not found on this Fritztrainer, as they are on a very high level, especially in terms of the subtleties in the opening, and Grooten's course aims to show and to accompany the first steps and concepts of the Hedgehog. Therefore, it's worth revisiting GM Pelletier's work!

About III:

Above I mentioned the significance of the d5 square, and sometimes White can sacrifice or pseudo-sacrifice a knight on d5:

The knight jump to d5 gains strength whenever it comes with pinning motifs along the c-file. There are cases when White sacrifices the knight and gets compensation, however, when the heavy pieces are lined up along the c-file, the move Nd5 is often a pseudo-sacrifce. And often it is strong. Usually, Black cannot allow White to exchange the knight on d5 against Black's bishop on e7 as the bishop is a key defender of Black's weak pawn on d6 and often important to create counterplay against the white king.

But after the sequence ...exd5 cxd5 and the subsequent capture on c6, Black is usually left with a ruin, not least because d5 can now be used by other white pieces. In the third chapter, the author talks about "shaving the spines," which is a fitting metaphor as it helps clarify some general strategic ideas.

Grooten also shows other ideas to put Black under pressure, e.g. the advance of the a-pawn, the breakthrough with c4-c5, which is usually first prepared by b2-b4, and the central breakthrough e4-e5.

Often, it's the black pawn on a6 that becomes a target for the white pieces in the endgame. And one must not forget that if the queens disappear from the board, the white king can quickly become active in the center via f2-e3-d4. Therefore, both sides need to keep an eye on possible breakthroughs that transpose to the endgame.

About IV:

The pawn breakthroughs ...d6-d5 and ...b6-b5 are examined in more detail in this section. Additionally, the plan introduced into tournament practice by Robert Fischer with reversed colors against Ulf Andersson (see above) is discussed. Nevertheless, it is worthwhile for Black to consider this attacking scheme:

Black's pieces are in very aggressive and promising positions, especially Black's bishop on c7 plays an important role in many positions after ...d6-d5, as the square h2 might become vulnerable. And Black's knight on f6 might go to h5 to threaten a devastating check on g3.

This position appeared in a blitz game between Sergey Kasparov and Sergei Azarov. Kasparov's namesake also plays the Hedgehog with Black and knows what Black can do. As a result, he has already played preventive moves like Kg1-h1 and Be3-g1 to safeguard the critical square h2. Still, Black has more firepower on the kingside, which makes the defense extremely challenging.

As mentioned earlier, such king-side attacks are the objective of the player with the black pieces. It's worth studying games by Sergey Shipov, who has also written two significant books on the Hedgehog. The following example is thematically related to the "breakthrough ...b6-b5":

This position arose in a game between Sergei Pestov and Sergei Shipov during an open tournament in Moscow in 1994.

The exchange of the white bishop on g2 often aids the player with the black pieces for two reasons. Firstly, the white king becomes more vulnerable to attacks, and secondly, control over the d5 square diminishes. It's also typical for the black queen to appear on b7 in such cases, from where it eyes g2 but also keeps an eye on the b5 square.

About V:

I particularly like this section because the author looks at White's various opening moves and explains how Black can reach Hedgehog positions after 1.e4, 1.d4, 1.c4, and 1.Nf3. However, usually, both players must be willing to enter a Hedgehog, which means that Black cannot always get a Hedgehog.

About VI:

In my opinion, the games of the Dutch author are particularly valuable because, being personally involved in these games, he describes the emotions and psychological effects well:

This position occurred between Ingo Böhme and Hermann Grooten in 1995 during an open tournament in Bochum, resulting in win for Black after 25 moves. Currently, the black position appears to be quite precarious, as the black king on e8 seems to be in great danger. However, the possibilities for Black are quite impressive, and the final position illustrates how much fun the pursuit of the white monarch can bring to Black:

Black's last move was 23...Rd2! and according to the author, his opponent almost fell from his chair when it appeared on the board. Such games remain in one's memory for a long time and emphasize the fighting spirit of the Hedgehog.


I find the exercises to be very well chosen, and they are accompanied by appealing commentary:

This position occurred between Igor Bjelobrk and Ian Rogers in 2004 during the Australian Championship, resulting in a victory for Black after 43 moves.

It appears as though the player with the white pieces has the situation well under control, but once again, the floodgates against the white king are opened with the move ...d6-d5.


This Fritztrainer is packed with instructive material on the Hedgehog, and even those without prior knowledge can learn a lot from the Dutch author. His extensive experience in conveying complex concepts is evident, and a solid grasp of basic English is sufficient to follow the explanations. Like the recent Fritztrainers, it also offers interactive tests, and the integration with ChessBase apps and streaming functions allows for convenient learning, often showcasing exemplary king-side attacks.

While players who opt for Hedgehog structures must accept a certain level of risk, the numerous attractive attacking opportunities make up for it.

I recommend this Fritztrainer to those who want to make the most of counterattacking chances and initiate king-side attacks with the black pieces. It allows you not only to play for a win but also to create attractive and aesthetically pleasing games!

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