IA. pawn Chains.
A pawn chain consists of two or more of a player’s pawns connected (lined up diagonally), where a rear pawn is protecting a vertically forward pawn one rank forward and in the file to the left or right of the rear pawn. The chain may be the simplest form – a two-pawn chain – or increase in size to three-pawn chains and four-pawn chains. A five-pawn chain is less frequently encountered in chess games. Imagine my surprise at coming across a six-pawn chain from an actual game (shown in the third diagram below).
The weakest link in a pawn chain is the rear most pawn as it is the “base of the chain” providing the initial protection for the chain. Attacking the base of a pawn chain primarily is a player’s best avenue to break the pawn chain, and open the vertically forward pawns to attack. That is the primary goal for attacking the base pawn chain, not just to capture that pawn (although that certainly can be beneficial in and of itself) but also to break the chain and hence its power. A nice example of attacking the base of a pawn chain is provided in David Bronstein’s book, 200 Open Games, at page 195 (full book reference provided in the Recommended Readings section).
Diagram PC-1 below shows the simple two-pawn chains established for both White and Black in the standard French Defense after Black’s second move consisting of advancing his or her pawn at d7 to d5, and White replying on his or her third move by advancing his or her pawn at e4 to e5 (as noted earlier this also creates a passed pawn for White). Diagram PC-2 shows the standard French Defense after four moves – Black concentrating early attack against the base of White’s pawn chain by Black’s pawn advance on Black’s third move (c5) followed by Black’s Queen Knight move on Black’s fourth move (Nc6).
Pawn chains created with passed pawns usually are especially threatening against an opposing player. The farther toward the opposing player’s home rank a player can establish a pawn chain with passed pawns, the more likely it may become a killer in the endgame phase.
In addition to single diagonal pawn chains, usually games develop where one or both players have multiple pawns chains on the board. These range from two or more single or multiple pawn chains that are isolated from each other, to more complex battle alignments involving two or more single or multiple pawn chains that are connected on the board. Connected pawn chains: two or more pawn chains connected with a single pawn at their apex. These can be in a “check mark” shape (e.g., a three pawn chain and a two pawn chain, a four pawn chain and a two pawn chain, etc.). However, more often these take the form of a V-shape pawn chain…two pawn chains connected in a V-shape pattern with a single forward pawn forming the apex of both pawn chains and the V-shape pawn chain. In addition, single or multiple pawn chains that are connected may be of two main types: forward or reverse or backward.
A forward connected pawn chain is where there are two more connected pawn chains with a single pawn on a forward square and the chains lined up behind it on the diagonals forming a “V-shape” vertically upwards toward Black’s home rank for White, and forming a “V-shape” vertically downwards toward White’s home rank for Black. This is usually the more powerful of the two types.
The reverse or backward connected chain (much weaker usually) is where the single pawn is to the rear of the connected pawn chain with the V-shape pawns of the chain aligned vertically upwards toward Black’s home rank for White, and vertically downwards toward White’s home rank for Black.
In a forward V-shape pawn chain when the apex pawn is a forward pawn vertically from the player’s side of the board, then there are two base pawns. With a reverse or backward V-shape pawn chain when the apex pawn is to the rear (i.e., toward the player’s home (back) rank), then it also is the base pawn in the chains. A reverse or backward pawn chain is usually much weaker than a forward V-shape pawn chain because if the base pawn falls to capture this opens up two of the player’s pawns (the next ones in the chain) to being attacked and captured, creating significant positional inferiority and double difficulties for the player. This brings into play another of the higher-level concepts…The Principle of Two Weaknesses. Therefore, with a reverse or backward pawn chain a player must usually commit one or more pieces to defense and protection duty to cover the positional weakness of the apex (base) pawn. This is not true for the forward V-shape pawn chain, because if one of the base pawns falls to capture then there is still another base pawn protecting the chain.
A player with well developed pawn chains can bring considerable attacking and threatening power against an opposing player, and often leads to a player deciding to begin advancing his or her pawns rapidly toward the opposing player’s home rank in a pawn storm. If the player times the pawn storm correctly, usually it devastates the opposing player forcing him or her to try to counter and defend against the pawn storm, thereby preventing him or her from further development of his or her own battle lines and position, cripples or completely blocks the opposing player’s ability to develop or continue with his or her own attack or counterattack, and often leads to a win for the player who is pushing the pawn storm because he or she likely will succeed in overwhelming the opposing player’s pieces and pawns, gaining one or more pawn promotion(s) gaining to additional fighting pieces and often crushing material superiority. The pertinent phrase is “times it correctly” … doing a pawn storm too early equally can be devastating to the player who commences it!