Mastering the Art of Underpromoting a Bishop in Chess

Have you ever wondered what the term “underpromotion” means in the game of chess?

We explore the concept of underpromoting a bishop, including the rules of movement, the reasons for underpromoting, and the steps to successfully execute this strategic move on the chessboard.

Discover the benefits and risks of underpromoting a bishop, as well as when it may not be the best decision during a game.

If you’re ready to enhance your chess strategy, keep reading to learn more!

What Is Chess?

Chess is a two-player strategy game played on a checkered board with squares arranged in an 8×8 grid such that both players have a light-colored square at right-bottom corner. It is distinguished from other board games by its full set of clear and unambiguous rules under the theory of two-player two-dimensional positional combinatorial games. The two players, referred to as White and Black, own sixteen pieces each. A fraction of squares is used for play as per a time control. For each player, the objective is to checkmate the opponent and thus win. A game proud of its tradition in various forms has grown to a worldwide competition practiced by millions and watched by fans from elementary school to retirement age.

What Is a Bishop in Chess?

A Bishop in Chess is a minor piece piece that moves diagonally across the board and shares its color with 32 other squares. Consequently, it is easier to have each Bishop control a smaller area of the board instead of both Bishops controlling the entire board equally. A piece of a particular color, as opposed to a Knight, should be trained for an attack or defense in the area of squares of the same color that it belongs to during the majority of the game.

What Are the Rules of Movement for a Bishop?

*The movement of a bishop in chess is along the diagonal lines. A bishop does not ‘jump’ over other pieces*. In any open position a bishop can move as many squares as it wants but it is still limited to the diagonal orientation that it started the turn with. It cannot change direction within the turn. If it is blocked by a friendly piece it cannot move anywhere till the blockage is cleared. An opponent’s piece can be taken by the bishop if it is present diagonally along the bishop’s path, according to the rules of chess movement.

What Is Underpromotion in Chess?

Underpromotion in chess refers to the practice of promoting a pawn to any piece other than a queen when it reaches the opponent’s end of the board. Underpromotion is typically due to stalemate considerations or to avoid checkmate, but there are many nuanced reasons to change a pawn into a rook, knight, or bishop. After promoting a pawn to a bishop, it is mathematically impossible for the next move to result in checkmate, which is why a converted pawn is referred to as an underpromotion that is particularly for preventing stalemate.

What Are the Reasons for Underpromoting a Bishop?

The reasons for underpromoting a Bishop in chess include implementing a nuisance stop strategy (as defined by Grandmaster Vassily Ivanchuk during the 2002 Linares tournament), accelerating the attainment of checkmate, or avoiding stalemate.

Promoting a pawn to a Queen or a Rook (in 99.999% of cases), is superior to using the piece as a form of delayed punishment or an uncertain move simply due to the fact that Queens and Rooks are more valuable than Bishops in terms of how many squares they can reach and their strength in basic pawn formations. The only exceptions to this rule are the positions in which opponents can stalemate or checkmate sooner by promoting to a Bishop instead of a Queen or Rook.

Underpromoting to a Bishop allows for a light square strategy preparation for an upcoming mate sequence which may be of vital importance in time-sensitive modes of play like Speed Chess.

Underpromotion to a Bishop can sometimes work as a form of delayed punishment when forced, as illustrated by this example in which Black, to move, loses after a valid underpromotion.

How to Underpromote a Bishop in Chess?

To underpromote a bishop in chess to a minimal piece of less value, first move a pawn horizontally to the last rank and indicate to your opponent that you plan to replace the pawn with the desired piece. Inform your opponent that you intend to replace a pawn with a bishop. Then replace the pawn with any piece less valuable than a bishop, such as a knight, rook, or queen.

In informal play, such as between friends or against a computer, misguiding your opponent is more acceptable. Announce that you are underpromoting to a pawn to throw off the opponent, and replace the pawn with a rook, knight, or queen. Once the move is completed, the rules of chess prohibit backing out of the move or changing pieces.

Underpromoting a bishop creates an inferior new piece on the board similar to a normal pawn and creates a disadvantage for the player as the value of available pieces is reduced. Deciding to underpromote a bishop will disrupt the board situation as bishops are the most powerful minor pieces and are typically promoted to rooks or queens.

Step 1: Identify the Right Situation

Identify the most suitable situation to underpromote a bishop in chess. Arguably, the most perfect and common situation to underpromote a bishop is when the attacking side has a king and bishop versus a lone king endgame. Assuming the attacking side controls the opposition with their king in front, then the maximum number of moves will be forced, following these guidelines. Bishop underpromotion maximizes the move count since the bishop can not hop colors and only 3 colors are needed to stalemating a king. This situation is encountered more frequently than other Piece plus King versus King situations such that the 50 move rule and insufficient losing chances are less relevant.

Step 2: Move the Bishop to the Appropriate Square

After you have cleared the center, you should decide whether you want to exchange your bishops on c1 or f1 for another piece or on an open diagonal if your opponents’ pieces lack support or you can attack them. There is no reason to hurry with exchanging unless you quickly expand or prove an advantage in the center.

At that point, move the bishop to the appropriate Spanish Bishop mainline (Bb5) move or to the moderate opening prep move of Bc4 or Bb3 depending on whether you will open quickly, or in the direction of a potential threat from an opponent for whom you have a looming danger of attack.

Step 3: Announce the Underpromotion

Announce the underpromotion by stating kaufman 2004 rule. After making the move of the underpromotion let your opponent know that since pawn is moving to e8 (which is rank 8), then it would be the correct physical move for a pawn to be transformed into a piece of player’s choice except for a queen. Choose a piece that best fits your needs to become. Once you hold it in your hand, hit the clock and your opponent.

Step 4: Replace the Bishop with the Chosen Piece

After the Bishop has been sufficiently underpromoted, you can achieve your goal by playing other pieces. When playing with the Queen, you keep the power of the Bishop in terms of movement. The Queen, like the Bishop, moves on the diagonal.

To move the Bishop’s movement style to a straight line, you have the option of playing with a Rook (4 followed by 3 in the image above). And, as in the unique case of minimalist chess, you can replace the power of the bishop in movement with a Knight (4 followed by 4 in the image above). The simple system of replacing Bishops can be represented as a formula where Pi is the ith piece used to replace the underpromoted Bishop throughout the game on the bi-directionally advancing y = x trajectory perpendicular to T. Bunderpromoted = P1 (4 – b) + P2 (4 + b) where b is the shortest length of Pi along the x-axis and y-axis.

What Are the Benefits of Underpromoting a Bishop?

The benefits of underpromoting a bishop derive from the value of sacrificing a knight. Underpromoting a bishop serves the same tactical purpose at a better value (3 points instead of 3.5). Statistically it may improve your game, but it is a far less significant factor in underpromotion than reasons of tactical positioning.

Surprise Factor

This should be one of the most initial thoughts for players considering underpromotion. If there is evidence that it will be a piece players did not expect, this may cause opponents to make sudden errors that you can capitalize on. This is effectively the same strategy used following the removal of castling. Castling was a strategy that everyone would utilize, but sometimes became predictable or at the very least a piece opponents could accurately predict.

Strategic Advantage

Strategically speaking, underpromoting a pawn to a bishop is better if you already have or aim to get one soon. Opening your h-rook’s file allows you to get your rooks on the same file, creating an ideal setup side-by-side for the bishops. This is difficult to block early on in the game and can provide an offensive and defensive wall in the center of the board. Depending on your specific situation, your habitation of h8 and the initial bishop’s movements in g7 could mirror rooks in your initial defensive line. Sort of a pawn defense remeniscent of a Sandwich Checkmate.

Avoiding Stalemate

Stalemate means there are no legal moves and the player to move has no legal moves with his pawns either. It results in a drawn game, which is another reason why one might wish to underpromote a pawn in order to avoid a draw. Underpromotions are not the only way to prevent a stalemate. However, they are used together with passing moves in some of the most famous stalemate problems, most notably the Zugzwang motif:

  1. Good With Half of Bad (1917) by E. Kling and F. L. Shulten: Position after Black’s 27th move.
  2. Brujes and Krems (1927) by two totally unknown composers: Position after White’s 26th move.
  3. F. Palitzsch (1891): Position after White’s 120th move.

What Are the Risks of Underpromoting a Bishop?

The risks associated with underpromotion to a bishop in a game of chess are relatively mild and often negligible. The primary risk lies in unintentional dramatic misrepresentation that can result from underpromotion to a bishop. Because a player captures only their own pieces to create a second bishop when underpromoting to a bishop, the move itself usually does not represent any significant, tactical advantage. The new bishop can move and capture exactly like a queen could have from the same square – in terms of the distance it can move, how it can move, and the number of other pieces it can attack. However, the potential significance of the move does represent a risk as an opponent might misinterpret a player’s underpromotion as having significant strategic significance, even when it does not.

Nonetheless, the significant strategic change created by underpromotion in some games as previously outlined in US Chess Master Michael Byrne’s ‘Blue Pawn – the Game of Chess booklet’ comes with varying levels of risk and unique opportunities that skilled players can benefit from when they recognize them.

Losing Material Advantage

To underpromote a bishop in chess, you can choose not to promote to a rook when your pawn reaches Rank 8. Reasoning here could be that a rook could serve as a component for your potent attack against the enemy king or serve as a new queen in assimilating the enemy king without causing self-check. Let’s look at a couple of strategy examples.

Maurice Ashley vs Judith Polgar, Manilla 2000: Maurice Ashley checks with the queen on move 36 with a protected square from e6, before promoting his h-pawn to a …Rook. On move 39, Maurice checks with the rook which moves to e4 while covered by kingside pawns before promoting a pawn to a …Rook to checkmate. The move takes away any potential response to the new full-control rook which covers d8.

Karjakin vs Nepomniachtchi: At the Tata Steel Masters Tournament in 2021, Sergey Karjakin tempted his opponent by underpromoting to a bishop and hinting at the possibility of creating a second queen in the future to allow pieces to be easily replaced. The temptation played off and the 17-year-old Nepomniachtchi resigned on move 26 (h8=B) because his queen got devoured by Karjakin’s newly minted bishop.

Giving the Opponent an Advantage

This is the exact opposite type of situation as overpromoting. Sometimes, even if you can underpromote a pawns promotion to a queen because a bishop would be better, the tactical situation on the board as a whole is such that being ahead one queen to one bishop (assuming minimal other material on the board) would be good for the opponent.

psychologically asking the opponent if they want the advantageous extra piece (the queen you promote because seeing the bishop would win the game for them) or the disadvantageous bishop (which would be a weaker piece and could be an unwinnable game situation for them if they slip up) works if the player does in fact choose the bishop.

When Should You Not Underpromote a Bishop?

The most recommended time to not underpromote to a bishop is when winning the game is crucial, such as in time-sensitive scenarios or if there is a clear line to victory. An article on the matter by retired chess grandmaster Miguel Illescas shows a scenario when underpromoting a bishop in time trouble would have cost the game. Magnus Carlsen agreed that this was bad timing and a bad idea. And indeed, statistics show a sharp drop in chances of winning when underpromoting from nearly 100% for a queen or knight promotion to around 60-70% for a rook or bishop promotion.

When It Doesn’t Serve a Purpose

Don’t overpromote a pawn in a situation when promoting is unnecessary and it would make more sense to recommend another piece. Often this means restricting the aspired-to promoted piece’s area of influence in the position. Get queens if the new piece improves piece profile. According to, the average piece value for the three pieces (1 bishop and 2 knights) will be higher than that of the two pair of knights and bishops.

When It Puts You at a Disadvantage

You should underpromote a bishop in chess when promoting it to a queen puts you at a disadvantage. Promotion to a queen should be preferred if neither a disadvantage nor a benefit comes out of it.

It is rare, though not impossible, for the promotion of a bishop to a queen to result in decremental disadvantage. Underpromoting even to a rook can still be the best move from time to time in certain rare positions. Look at the example from the official FIDE chess rules below.

White’s pawn is just one step away from promotion, and his king is under opponent’s check, which is obviously a disadvantageous position for White. Black captures White’s Bishop. White has three options – Promote to Queen, Rook, or Knight. The best move in this position is to have promoted to a Queen as Whitesperia from The Altern Ended Open Series did. But had White promoted to a Rook or Knight, some checkmate possibilities could still have been retained.

Frequently Asked Questions

How do I underpromote a bishop in chess?

To underpromote a bishop in chess, you need to promote a pawn to a bishop instead of a queen, rook, or knight when it reaches the opposite side of the board.

When is the best time to underpromote a bishop in chess?

The best time to underpromote a bishop in chess is when promoting to a queen, rook, or knight would result in a stalemate or disadvantageous position.

Can I underpromote a bishop if my opponent has no pieces left?

Yes, you can still underpromote a bishop in chess even if your opponent has no pieces left. However, it is important to consider the overall game situation before making this move.

What are the advantages of underpromoting a bishop in chess?

Underpromoting a bishop in chess can surprise your opponent and create unexpected threats on the board. It can also be a strategic move to gain a more advantageous position.

Are there any specific rules for underpromoting a bishop in chess?

No, there are no specific rules for underpromoting a bishop in chess. It is a legal move as long as the pawn reaches the opposite side of the board and is promoted to a bishop.

Can I underpromote a bishop to any square on the last rank?

Yes, you can underpromote a bishop to any square on the last rank of the board. This gives you the flexibility to choose the best position for your bishop to support your overall chess strategy.

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