II.     Passed pawns

A passed pawn occurs when a player advances one of his or her pawns past the ability of an opposing pawn in a file to the left or right (a forward diagonal square) to capture the pawn that is advanced, and there is no opposing pawn in the file to block the advance of the pawn . A passed pawn also may occur by doing a pawn capture that results in the capturing pawn also advancing past the ability to be blocked or captured by a defending opposing pawn. Conceptually, passed pawns may be viewed for tactical and strategy purposes in two diferrent ways: absolute and partial

1. The primary definition of passed pawn conceptually may be viewed as an absolute passed pawn, which is a pawn located on a square with no opposing pawn in the file which may block its move or on a forward diagonal square either in the file to the left or right that may capture the passed pawn. Therefore, usually, the passed pawn may not be blocked from vertically advancing or be captured to prevent pawn promotion except by an opposing piece. However, the position on the board might be such that the opposing player is able through a pawn capture to diagonally advance one of his or her pawns to the file in which the passed pawn is located to act as a block or through a capture into a position in an adjacent file to the right or left of the file in which the passed pawn is located, and vertically ahead of the pawn if the passed pawn is White’s pawn, or vertically downward if the passed pawn is Black’s pawn, so as to bring the opposing pawn into position as a defender against the passed pawn. The passed pawn then would no longer be an absolute passed pawn, but would become a “partial passed pawn”.
2. A player should also consider the “conceptual” partial passed pawn (admittedly not a passed pawn in within the above primary definition). This in a pawn that has:     a. has passed an opposing pawn in either the file to the right or to the left of the file in which the passed pawn is located; orb. has passed the opposing pawn in the file in which the pawn is located; or

   c. has no pawn in either the file to the right, or the file to the left, of the file in which the pawn is located.

   However, there remains either an opposing pawn in the file in which the pawn is located and/or in one of the adjacent files that may act as a defender against the passed pawn advancing toward pawn promotion. The word “partial” is used to denote that a player might be able to exploit the file in which there is no opposing pawn to the right or left for tactical and strategic purposes.

   Below are some diagrams to assist is understanding these concepts. The first set of two diagrams shows an absolute passed pawn for Black at a6 (no opposing pawn in the a file or b file). There also are partial passed pawns for White and Black at e3 and e6 because there are no opposing pawns in the d file. The third diagram shows partial passed pawns for Black at a5 (no opposing pawn in the a file but a defender opposing pawn at b3) and for White at b3 (no opposing pawns in the b file or c file, but defender opposing pawn at a5). The diagram also continues to show the partial passed pawns for White and Black at e3 and e6 as in the other two diagrams (no opposing pawns in the d file). In the third diagram, Black’s Bishop at d1 is doubly attacking White’s partial passed pawn along with Black’s Queen. White’s partial passed pawn at b3 is defended only by White’s Queen. Thus, White is going to lose the partial passed pawn at b3 and Black will gain an absolute passed pawn with the a5 pawn. For example, if it is Black to move then 1…Bxb3 and White loses its passed pawn and Black gains an absolute passed pawn, which White will not be able to prevent from being promoted without giving up White’s Queen. If it is White to move, regardless what White does eventually the same or a similar result would occur where Black would gain an absolute passed pawn that White could only stop from pawn promotion by giving up White’s Queen.

General Principles for Passed pawns

1. A Knight is the best blockader of a passed pawn.
2. A passed pawn is not always a positive thing to have. A blocked passed pawn may have significant negative consequences for a player because it also may represent a block in files and diagonals for a player’s other pieces (the Bishops and the Rooks) and gives the opponent an opening to advance a piece to a key square (the one in front of the passed pawn) which might not otherwise be available if the passed pawn was not providing a shield against a capture.
3. A passed pawn that gets safely past the player’s fifth rank (rank 5 for White, and rank 4 for Black) represents a significant threat in the usual course of a game. [an advanced passed pawn also is called a distant passed pawn;
4. A passed pawn is strongest in a Queen endgame.;
5. An Outside Passed pawn is a passed pawn that is the farthest distance away from an opposing King [also is called a Remote Passed pawn;
6. Rooks always belong in back of passed pawns, not in front of them. A Rook in front of a passed pawn blocks the passed pawn from advancing and promoting, therefore the Rook must move out of the file for it to be able to advance and possibly promote and hence out of being able to act as a defender of the passed pawn, thereby subjecting it to possible attack and capture by the opponent.

According to the standard scale (material point value), a Knight is worth three pawns, so two pawns are worth less than a Knight. That makes sense. Ah, but not necessarily always where passed pawns are concerned. David Bronstein in his book, 200 Open Games [full reference in the Recommended Readings section], at page 134 reviewing his game against Ya. Klayvin (Ya. Klavin – Bronstein, Moscow 1960, USSR Team Championship) and Black’s ability to develop a four pawn chain on the Kingside, observed that “two pawns are worth less than a [K]night, but connected passed pawns…They are often priceless!” I recommend you review this game, because it is an excellent example of making connections between material advantage, tactics, strategy, positional structure, and pawn structure. The vitality of pawn chains (connected pawns; and if two pawns are connected but not connected with other pawns of a player, also called a pawn island) coupled with passed pawns are often very, very powerful against an opponent, sometimes even if he or she has a material advantage!!! Another nice observation by Mr. Bronstein: “Whoever creates a distant passed pawn first usually wins the game.” (200 Open Games at page 144).

The Ya. Klavin – Bronstein game after White’s 45th move is shown in the diagram below. While the game ended in a draw by agreement because Black allowed White to weaken the power of Black’s pawns by rushing in the endgame (a nice note of caution from Mr. Bronstein about playing too fast!), White earlier erred in engaging in an exchange of the Queens allowing Black to regain the initiative. So instead of Black losing a whole point, Black was able to salvage a split 1/2 – 1/2. Mr. Bronstein opined that his Queen move to c4 (or QB5 in English Descriptive notation utilized by him in his book) on his 21st move was a decisive factor in saving the 1/2 point for him. I am quite sure Mr. Bronstein did not foresee at the 21st move the exact manner in which the game played out, but this shows the value later in the game of making powerful moves which do not in the immediate future play out decisively in and of themselves, but instead lie hidden in waiting for an opportunity.