Named Pawn Formations

Over centuries of chess theory, certain recurring pawn skeletons have earned their own names, because each one comes with its own well-understood plans, strengths, and weaknesses for both sides -- recognizing the pattern immediately tells an experienced player roughly what kind of game to expect. This module covers five of the most common: the Isolated Queen's Pawn, Hanging Pawns, the Stonewall, the Maroczy Bind, and the Hedgehog.

The Isolated Queen's Pawn (IQP) is a lone pawn on the d-file with no friendly pawn on c or e -- it's an isolated pawn specifically in the center, which trades long-term structural weakness for extra space and open lines for pieces. Hanging Pawns are two connected pawns (usually c and d) with open files immediately outside both of them -- mobile and space-gaining, but losing either one instantly isolates the other.

The Stonewall is the d4/e3/f4 skeleton (mirrored d5/e6/f5 for Black) that locks the center solid in exchange for a long-term kingside attack, at the cost of permanently boxing in the light-squared bishop. The Maroczy Bind is pawns on c4 and e4 with no d-pawn, clamping down on the d5 square and cramping the opponent's whole position -- common against the Sicilian and Symmetrical English. The Hedgehog is a coiled, compact black (or white) formation tucked on the 6th (or 3rd) rank, deliberately passive early on while waiting for a well-timed pawn break to spring open.

A single position can only match one of these named skeletons at a time in this module's detector -- they're recognized by their exact defining shape, not judged for whether they're actually good in the specific position they appear in.