There are lots of situations where a promotion to a queen would result in stalemate (draw) so a promotion to rook or other piece gets away form this. I'd say Rook would be most common, but some special (problem?) positions a knight or bishop could solve the problem with a mate or a nice fork. E.g. promote to a night with check and an attack on the opponents queen.
It's interesting that all these positions are called "common", but the actual board position might happen zero to one times in a lifetime, and I suspect it's usually zero times.
I noticed something similar when I played contract bridge at a competitive level. A top bridge player might play very roughly on the order of 10,000 hands a year, and vividly recall something that happens on the order of once a year as "oh yeah that's common". Of course I wasn't remotely close to them. But there is something about competitive games that seem to amplify the memory for certain kinds of unusual situations.
(Some people are commenting about under promoting to avoid stalemate traps down the line. I've always been a weak chess player, but... trying to set a stalemate trap after being down a queen, in a non-contrived position, is, like, adult chess players shouldn't do that. In my limited experience.)
Knight promotion because it's the best piece in the situation happens often. Rook promotion because Queen promotion would be stalemate happens occasionally. Bishop promotion is a theoretical curiosity only.
Well, maybe. There's no full record of the game, it's not even clear which year it supposedly took place in. It could have been a real tournament game, but I don't think there's enough evidence to reasonably conclude that it was.
Just to pile on, a common trick is to sac a queen for say a minor piece, then after king takes queen, a pawn is promoted to a knight with check and a fork on the queen. After the dust settles, a player is up a minor piece.
A knight will attack different squares than a queen so promoting to a knight of course makes obvious sense in situations that warrant.
A rook or a bishop attack a subset of squares that a queen does, so why would you ever pick one of them instead of a queen? To avoid the stalemate where your opponent is not in check but has no legal moves.
The juiciest one is the Albin Counter-gambit. If you follow the "ideal line" where white blunders and takes the bishop bait, there's a neat knight underpromotion to win a queen.
From my own play, I typically see knight f3 from white on move 4, which still results in interesting games.
> There are lots of situations where a promotion to a queen would result in stalemate
You disagree with their 'rare' then where is your analysis?
You gave zero numbers or evidence, you're just saying stuff that pops into your head.
This analysis is a 35 to 1 for queens, knights arethe most popular alternative but I don't believe they played out the opponent resigns which most people do before the promotion to queen or analysised shit/fun playing -
Lichess has a series of puzzles you can try where underpromotion is the theme (which is unfortunately a major giveaway to solving these puzzles, since they otherwise be rather hard to solve)
I had known of stalemate (both causing and preventing it), but there are others as they mention there.
One other I think I have read about (I do not entirely remember) is that someone promoted to rook because promotion to queen would have taken more time due to not having a extra queen to promote to so they would have to go to another table to borrow it (or ask the tournament officials for it).
Most recreational players have probably underpromoted to a rook at some point to avoid stalemate. I do it online as a matter of course if a rook underpromotion would be immediate checkmate because a rook is all you need so why ask for more.
Bishop is extremely rare but it does happen. For example there was the famous case in the US champs when Fabiano Caruana underpromoted to a bishop[1] vs Ray Robson and Robson immediaely resigned. https://youtu.be/umabaHAGmJQ?si=ETy1cAFw7ydH4MhH
[1] He didn’t have to- he just did it because he had never done it in his whole chess career
I've promoted to rook several times in over-the-board tournaments.
It's easier and quieter than stopping the clock and searching for a free queen piece if your position is decisive and your opponent stubborn. Or your piece to be captured immediately.
So not necessarily "cocky" as the answers suggest but rather "mindful to other players".
Conversely, I could see a situation where a queen is available but will be captured right away, so you under-promote to a piece that is not immediately available so you can stop the clock while the arbiter finds the piece you need. If you are in time trouble this could give you some much needed time to reassess the position.
Why would you need to search for a queen piece when yours is already captured? No doubt promoting to multiple queens happens in casual games between very weak players, but extremely rarely in tournament play (where you also don't see "stubborn" players playing on in "decisive" positions unless the winning side has very little time on the clock).
Also, for in-person games, an upside down rook can be used as a queen in a pinch.
It's more common than you think in queen and pawn endgames. It might even end in a dear with two queens in one side: It wasn't on the board because there were other fighting alternatives, but it was pretty close to happening just last week in the Grand Chess Tour finals, where Caruana saw that a second queen wouldn't stop MVL from getting a perpetual.
I'd not say it happens in every tournament, but many active tournament players will see it every year or two. It just happens that at the higher levels, chances are the set came with two queens, as upside down rooks are not great indicators for DGT boards.
The stubborn player situation will happen in real tournaments too, just not those full of GMs. It will happen in your typical rated weekly tournament in the St Louis chess club, where your top tables might not be IMs, or in scholastic tournaments.
As stated it's wrong--there aren't special rules for "serious play" as opposed to non-serious play. However, it's illegal under FIDE rules, but allowed under USCF rules (which cover many "serious" tournaments).
And I'm amused by another response that says that it's more common than I think and then cited a case where it "almost" happened, and says "many active tournament players will see it every year or two", as if that's not "extremely rare".
Restatement of the premise is not an explanation. I asked "why."
> However, it's illegal under FIDE rules
Under which rule[1]? I anticipate the argument being one of identity, such as "a rook is a rook whether it is right side up or upside down." This is an argument of convention. I don't see a CAD model that describes a rook's physical representation. If both players were to agree that for the sake of a promotion that an overturned rook would in fact be played like a queen the piece identity requirement would be satisfied and no descriptive rule would be violated. Or perhaps a coin, or a stone, or anything of suitable size and ergonomics.
I didn't "restate the premise", I said it was wrong, and added information. Since I wasn't present when the FIDE hammered out their rules, I don't know why they decided that upside down rooks can't be used as queens, and any speculation on my part would be no more authoritative than your own imagination.
I tried to be helpful and I got an aggressively hostile response. (And I see that the same happened to others here.) I won't make that mistake again.
> When a player places an inverted (upside–down) Rook on the promotion square and continues the game, the piece is considered as a Rook, even if he names it as a “Queen” or any other piece. If he moves the upside-down rook diagonally, it becomes an illegal move.
This is not a philosophical question about metaphysics, where the rook’s true essence can be converted to that of a queen because really, what are the queens and rooks anyway but abstract symbols? The rook is the physical object that everyone in the tournament hall recognizes as a rook, which nobody has a problem identifying in practice.
That's interesting, but I wonder if it's not more accurate to say "tradition doesn't support the use of an inverted rook as a promoted queen's proxy" or "FIDE would prefer not using inverted rooks as a promoted queen proxy" instead? Unfortunately neither explain why this is the preference, but avoiding ambiguity for observers seems obvious.
My thinking is that if we take "many active tournament players will see it every year or two" as the absence of a strict prohibition, and that this description of how it is illegal occurs in the "Arbiters' Manual," which self-describes as guidelines for arbiters and in the preface explains that rules can't cover every situation which is why the arbiters exist, but not in the actual rules document, it seems less "illegal" and more "unadvised."
I did not wax metaphysical, quite the opposite with the desire to find a definition for how one identifies a given piece. I imagine there are some other tournament organizational guidelines which outlines how chess sets are chosen for official events. These conventions taken in aggregate would provide some perspective, but still not answer the original question. I wager that everyone in your tournament hall would also recognize the use of an inverted rook as a promoted queen. So if it's not a question of avoiding ambiguity, then I wonder again, "why?"
There is a shorter version of this reply, which I will now include below:
At the end of the table of contents there is another interesting note in an offset grey box, just like the box which contains the note you quoted above:
> IMPORTANT:
> Throughout this manual, text which appears in a box such as this one is given as advice and is
the opinion of a number of experienced arbiters. It does not form part of the Laws nor the
Regulations in which it appears.
> That's interesting, but I wonder if it's not more accurate to say "tradition doesn't support the use of an inverted rook as a promoted queen's proxy" or "FIDE would prefer not using inverted rooks as a promoted queen proxy" instead?
No, it is against the FIDE rules. Both the official rules, and the unofficial explanatory text in the Arbiter's Manual. The official rules say that chess sets contain a piece called a queen, and a piece called a rook. They do not say anything about a piece other than a queen becoming a queen if it is turned in a different orientation, so it should be obvious that it doesn't do so.
But even for those for whom that wasn't obvious, there is additionally the arbiter's manual, explaining that yes, this is in fact the interpretation of the rules that FIDE and senior arbiters believe to be correct.
Despite all this you are refusing to believe it's actually against the rules. I am not sure what else I can cite to convince you. Google, ask your favorite LLM, or ask a FIDE arbiter if you want -- everyone will agree that if you promote to a rook, it is a rook, regardless of whether it's upside down or not.
Nobody has written a formal definition of which piece in a chess set is "the rook" and which one is "the queen", because the FIDE rules were not written by formal logicians, and so it probably never occurred to them that this was necessary.
This simply never comes up. You are probably the only person in history from the founding of FIDE until now who has pretended not to know what a rook or a queen is.
> My thinking is that if we take "many active tournament players will see it every year or two" as the absence of a strict prohibition
I think you are misinterpreting that comment. They are saying those players will see a scenario with two queens of one color on the board every year or two, not that they'll see someone trying to use an upside-down rook to stand for one of them.
> They are saying those players will see a scenario with two queens of one color on the board every year or two
That makes sense.
It seems to me that you've used a lot of truism reasoning out of frustration. I tried to head these off with my original assumption that it was a question of identity.
>> I anticipate the argument being one of identity, such as "a rook is a rook whether it is right side up or upside down." This is an argument of convention.
Since the reliance is on convention, and an inverted rook is conventionally treated as a promoted queen, the FIDE Arbiters' Manual describes a policy of not following this convention. I'm sure someone knows why this is the guidance. I was curious about that reasoning. It seemed interesting and worthy of discussion.
> You are probably the only person in history from the founding of FIDE until now who has pretended not to know what a rook or a queen is.
You ascribe to pretend ignorance what is in fact interest in the history of a thing. This seems unreasonably antagonistic.
I believe you've misunderstood my original comment and I do not know why, but I think I will be done with this thread. If you find out why this was the adopted guidance for the FIDE Arbiters' Manual I'd enjoy reading about it and I imagine others may too, but it should be put under the original question, not here.
> Since the reliance is on convention, and an inverted rook is conventionally treated as a promoted queen
I think that convention is much less strong than the conventional meaning of the piece shapes. I have only seen it in casual games, and I’m not sure if it exists in every country.
I don’t know why this rule was adopted, but I gave a few plausible reasons off the top of my head in another post on this thread.
The discussion was about tournament rules, not what you do at Christmas, where the FIDE rules have no jurisdiction. And even if they did, what are these "special rules"? I don't think that you made a serious attempt to engage with what I wrote but instead were intent on naysaying, so I won't comment further.
Apparently it’s allowed under USCF (US Chess Federation) rules, according to my sibling comment, just not under FIDE (international) rules.
Anyway, I’ve never stopped and thought about why it’s not allowed — it just seems like it obviously shouldn’t be, in serious competition. If at an NBA game they ran out of basketballs, they’d stop the game until they got one, not use a soccer ball instead.
It’s hard to imagine that at an actual FIDE-rated tournament with arbiters, etc., they would be unable to find a queen piece to use.
> it just seems like it obviously shouldn’t be, in serious competition
Why does it seem obvious? Out of some sense of accessibility to third party observers?
> If at an NBA game they ran out of basketballs, they’d stop the game until they got one, not use a soccer ball instead.
This is an unreasonable straw man because basketballs and soccer balls behave quite differently. A marble would be less suitable than an overturned rook because it may roll away, but both are similarly graspable with similar dexterity.
> Why does it seem obvious? Out of some sense of accessibility to third party observers?
I can think of lots of reasons.
1. It looks cheesy and unprofessional to use random objects instead of the pieces the game is supposed to be played with; you might not think this is a good reason but keep in mind we are talking about a game that until recently everyone played wearing a suit and tie.
2. It is distracting and impedes comprehension and calculation if the design of the actual pieces is burned into your pattern recognition — not only for observers, but for the players themselves. A lot of official chess rules, e.g. the touch-move rule, are just about not annoying your opponent.
3. It opens up ambiguity about what was actually intended. What if later the player tries to claim they really did mean a rook? What if a player accidentally turns one of their actual rooks upside down during the course of a game — is it still a rook, or are they trying to cheat by turning it into a queen? Etc.
4. It does not work with high-end electronic chessboards that automatically record moves (DGT).
5. Last but not least: there is absolutely no reason to allow this, because it’s impossible to imagine that at a serious tournament the arbiter wouldn’t be able to find an extra queen. And stopping the clock and asking for an arbiter, while still a bit distracting to others, is surely less distracting than starting a discussion with the opponent about whether it’s okay to use an overturned rook or any other random object as the queen.
Underpromotions to rook or bishop certainly can happen in play to avoid stalemating the opponent and preserving the win. Other reasons don't exist in play (aside from extraneous reasons like not having a queen handy or weak players underpromoting just because they are afraid of stalemating even though promoting to a queen wins) but can in compositions. e.g., here's a position that is the other way around, where promotion to a bishop is stalemate regardless of where the opponent moves and any other promotion loses:
P.S. https://timkr.home.xs4all.nl/chess2/minor.htm contradicts my "Other reasons don't exist in play", assuming that the game that he analyzes actually happened, which is questionable.
I played chess for only a few years, at a low level, and I encountered situations where underpromotion to a bishop or rook was necessary to win. It's possible it is more common at the just-above-beginner level than at the elite level, because a player in a losing position will play on longer and try to set up stalemate traps that would be pointless in higher-level games.
The unspoken assumption here would be promoting to rook or bishop "instead of a queen" and as the post points out other than avoiding the stalemate situation there doesn't appear to be a logical reason for doing this.
There are puzzles where only a bishop promotion wins. The others are either forced stalemate or forced draw by repitition. Finding a real game where that happens is unlikely
It probably wouldn’t ever happen in a real game, but I think it’s possible to be in a situation where you’re still losing after promoting to a queen, but underpromoting to a bishop forces a stalemate by leaving you with no legal moves no matter what your opponent plays in response.
Indeed it wouldn't happen in a game but ... I easily created a position where promotion to a bishop is stalemate after any black move (confirmed by Stockfish):
White pawns on a7 and b7, king on h8. Black king on f2, bishop on g3, rook on h3, knights on a6 and b8, pawns on c6, d7, f3, and h2.
This position is a draw after a8=Q or axb8=Q but that is easily remedied by adding black pieces, e.g., a queen on h4.
I have read that underpromotion can reduce the risk of immediate capture: the opponent has a bigger incentive to take a queen than, say, a rook. Seems pretty marginal to me though.
It's better to force the opponent to capture than give him the choice of capturing or doing something else. If your opponent chooses not to capture the rook it's because he has found a move he thinks is even better than taking the rook. And that move is then something you should fear.
A big part of chess is maximizing your own choices and freedom while restricting your opponents choices.
Level 1, yes, this is the correct way of thinking. You should always take the highest scoring move.
However, Level 2, making a decision harder for your opponent, might force them to spent more time thinking about the decision. If for some reason there is an imbalance of pondering, this might be beneficial. Suppose that you knew X position would be reached before your opponent, so you had more time to study it, you know what the correct piece to take is, whether a promoted rook, or a previously existing rook, but your opponent doesn't yet, and crowning to a queen will force your opponent into a move without a thought.
The computer will sometimes do this, more because of randomness than strategy, but it is probably always the case that if they underpromote, you should take, it's like a tell of theirs. Perhaps there is a case for nash equilibirum where you must sometimes offer an underpromotion in a scenario where a queen would have been marginally better such that underpromoting doesn't signal to your opponent that they should take the piece (whichever it may be, I'm a bit dizzy)
Very theoretical, but not impossible that underpromoting in such scenarios might be beneficial, that said, very theoretical.
Stats I’ve seen are that around 2% of games between grandmasters include a promotion.
What you might be overlooking is that often the player that promotes might have temporarily given up material in order to get the promotion so it is may just be restoring approximate equality.
Or it could be that the second player will also promote soon.
Resignation is a signal that you know your opponent knows how to win so why waste everyone's time playing it out. For high level players you can be confident they know how to win but there might be more than 100 moves left in the game, so not wasting time playing out a losing game is the polite thing.
When playing someone low rated your opponent isn't good enough to think they can win unless there are less than 3 moves left so you may as well just play the rest of it out at that point. Even then, if you are in a simple (rook?) endgame if the low rated player makes a couple right moves you can assume they know the remaining moves so is it worth wasting your time to prove it?
That all depends on time control. If you watch Titled Tuesday for instance you'll see plenty of games where a player promotes and their opponent doesn't concede hoping to get a stalemate or a dirty flag.
There's a very chill streamer named Eric Rosen that does stalemate tricks at all levels, and it's surprising how often he gets them to work (even with super GMs from time to time).
I noticed something similar when I played contract bridge at a competitive level. A top bridge player might play very roughly on the order of 10,000 hands a year, and vividly recall something that happens on the order of once a year as "oh yeah that's common". Of course I wasn't remotely close to them. But there is something about competitive games that seem to amplify the memory for certain kinds of unusual situations.
(Some people are commenting about under promoting to avoid stalemate traps down the line. I've always been a weak chess player, but... trying to set a stalemate trap after being down a queen, in a non-contrived position, is, like, adult chess players shouldn't do that. In my limited experience.)
https://timkr.home.xs4all.nl/chess2/minor.htm
With a queen it's too easy to make a mistake and get a draw because the other player can't move.
A rook or a bishop attack a subset of squares that a queen does, so why would you ever pick one of them instead of a queen? To avoid the stalemate where your opponent is not in check but has no legal moves.
From my own play, I typically see knight f3 from white on move 4, which still results in interesting games.
You disagree with their 'rare' then where is your analysis?
You gave zero numbers or evidence, you're just saying stuff that pops into your head.
This analysis is a 35 to 1 for queens, knights arethe most popular alternative but I don't believe they played out the opponent resigns which most people do before the promotion to queen or analysised shit/fun playing -
https://blog.ebemunk.com/visual-look-at-2-million-chess-game...
https://lichess.org/training/underPromotion
One other I think I have read about (I do not entirely remember) is that someone promoted to rook because promotion to queen would have taken more time due to not having a extra queen to promote to so they would have to go to another table to borrow it (or ask the tournament officials for it).
Bishop is extremely rare but it does happen. For example there was the famous case in the US champs when Fabiano Caruana underpromoted to a bishop[1] vs Ray Robson and Robson immediaely resigned. https://youtu.be/umabaHAGmJQ?si=ETy1cAFw7ydH4MhH
[1] He didn’t have to- he just did it because he had never done it in his whole chess career
It's easier and quieter than stopping the clock and searching for a free queen piece if your position is decisive and your opponent stubborn. Or your piece to be captured immediately. So not necessarily "cocky" as the answers suggest but rather "mindful to other players".
Also, for in-person games, an upside down rook can be used as a queen in a pinch.
I'd not say it happens in every tournament, but many active tournament players will see it every year or two. It just happens that at the higher levels, chances are the set came with two queens, as upside down rooks are not great indicators for DGT boards.
The stubborn player situation will happen in real tournaments too, just not those full of GMs. It will happen in your typical rated weekly tournament in the St Louis chess club, where your top tables might not be IMs, or in scholastic tournaments.
Btw, the upside-down-rook trick is illegal in serious play.
Using a proxy piece seems like an expedient, reasonable solution. A small square of paper with a Q on it?
And I'm amused by another response that says that it's more common than I think and then cited a case where it "almost" happened, and says "many active tournament players will see it every year or two", as if that's not "extremely rare".
Restatement of the premise is not an explanation. I asked "why."
> However, it's illegal under FIDE rules
Under which rule[1]? I anticipate the argument being one of identity, such as "a rook is a rook whether it is right side up or upside down." This is an argument of convention. I don't see a CAD model that describes a rook's physical representation. If both players were to agree that for the sake of a promotion that an overturned rook would in fact be played like a queen the piece identity requirement would be satisfied and no descriptive rule would be violated. Or perhaps a coin, or a stone, or anything of suitable size and ergonomics.
[1] https://www.fide.com/FIDE/handbook/LawsOfChess.pdf
I tried to be helpful and I got an aggressively hostile response. (And I see that the same happened to others here.) I won't make that mistake again.
> When a player places an inverted (upside–down) Rook on the promotion square and continues the game, the piece is considered as a Rook, even if he names it as a “Queen” or any other piece. If he moves the upside-down rook diagonally, it becomes an illegal move.
Link: https://arbiters.fide.com/wp-content/uploads/Publications/Ma...
This is not a philosophical question about metaphysics, where the rook’s true essence can be converted to that of a queen because really, what are the queens and rooks anyway but abstract symbols? The rook is the physical object that everyone in the tournament hall recognizes as a rook, which nobody has a problem identifying in practice.
My thinking is that if we take "many active tournament players will see it every year or two" as the absence of a strict prohibition, and that this description of how it is illegal occurs in the "Arbiters' Manual," which self-describes as guidelines for arbiters and in the preface explains that rules can't cover every situation which is why the arbiters exist, but not in the actual rules document, it seems less "illegal" and more "unadvised."
I did not wax metaphysical, quite the opposite with the desire to find a definition for how one identifies a given piece. I imagine there are some other tournament organizational guidelines which outlines how chess sets are chosen for official events. These conventions taken in aggregate would provide some perspective, but still not answer the original question. I wager that everyone in your tournament hall would also recognize the use of an inverted rook as a promoted queen. So if it's not a question of avoiding ambiguity, then I wonder again, "why?"
There is a shorter version of this reply, which I will now include below:
At the end of the table of contents there is another interesting note in an offset grey box, just like the box which contains the note you quoted above:
> IMPORTANT:
> Throughout this manual, text which appears in a box such as this one is given as advice and is the opinion of a number of experienced arbiters. It does not form part of the Laws nor the Regulations in which it appears.
No, it is against the FIDE rules. Both the official rules, and the unofficial explanatory text in the Arbiter's Manual. The official rules say that chess sets contain a piece called a queen, and a piece called a rook. They do not say anything about a piece other than a queen becoming a queen if it is turned in a different orientation, so it should be obvious that it doesn't do so.
But even for those for whom that wasn't obvious, there is additionally the arbiter's manual, explaining that yes, this is in fact the interpretation of the rules that FIDE and senior arbiters believe to be correct.
Despite all this you are refusing to believe it's actually against the rules. I am not sure what else I can cite to convince you. Google, ask your favorite LLM, or ask a FIDE arbiter if you want -- everyone will agree that if you promote to a rook, it is a rook, regardless of whether it's upside down or not.
Nobody has written a formal definition of which piece in a chess set is "the rook" and which one is "the queen", because the FIDE rules were not written by formal logicians, and so it probably never occurred to them that this was necessary.
This simply never comes up. You are probably the only person in history from the founding of FIDE until now who has pretended not to know what a rook or a queen is.
> My thinking is that if we take "many active tournament players will see it every year or two" as the absence of a strict prohibition
I think you are misinterpreting that comment. They are saying those players will see a scenario with two queens of one color on the board every year or two, not that they'll see someone trying to use an upside-down rook to stand for one of them.
That makes sense.
It seems to me that you've used a lot of truism reasoning out of frustration. I tried to head these off with my original assumption that it was a question of identity.
>> I anticipate the argument being one of identity, such as "a rook is a rook whether it is right side up or upside down." This is an argument of convention.
Since the reliance is on convention, and an inverted rook is conventionally treated as a promoted queen, the FIDE Arbiters' Manual describes a policy of not following this convention. I'm sure someone knows why this is the guidance. I was curious about that reasoning. It seemed interesting and worthy of discussion.
> You are probably the only person in history from the founding of FIDE until now who has pretended not to know what a rook or a queen is.
You ascribe to pretend ignorance what is in fact interest in the history of a thing. This seems unreasonably antagonistic.
I believe you've misunderstood my original comment and I do not know why, but I think I will be done with this thread. If you find out why this was the adopted guidance for the FIDE Arbiters' Manual I'd enjoy reading about it and I imagine others may too, but it should be put under the original question, not here.
I think that convention is much less strong than the conventional meaning of the piece shapes. I have only seen it in casual games, and I’m not sure if it exists in every country.
I don’t know why this rule was adopted, but I gave a few plausible reasons off the top of my head in another post on this thread.
Of course there are. We don’t follow every rule in the FIDE handbook when I play at Christmas with my brother in law.
For example, I would bet that in 99% of home games, touch-move is not enforced.
> allowed under USCF rules
interesting, I didn’t know that.
Anyway, I’ve never stopped and thought about why it’s not allowed — it just seems like it obviously shouldn’t be, in serious competition. If at an NBA game they ran out of basketballs, they’d stop the game until they got one, not use a soccer ball instead.
It’s hard to imagine that at an actual FIDE-rated tournament with arbiters, etc., they would be unable to find a queen piece to use.
Why does it seem obvious? Out of some sense of accessibility to third party observers?
> If at an NBA game they ran out of basketballs, they’d stop the game until they got one, not use a soccer ball instead.
This is an unreasonable straw man because basketballs and soccer balls behave quite differently. A marble would be less suitable than an overturned rook because it may roll away, but both are similarly graspable with similar dexterity.
I can think of lots of reasons.
1. It looks cheesy and unprofessional to use random objects instead of the pieces the game is supposed to be played with; you might not think this is a good reason but keep in mind we are talking about a game that until recently everyone played wearing a suit and tie.
2. It is distracting and impedes comprehension and calculation if the design of the actual pieces is burned into your pattern recognition — not only for observers, but for the players themselves. A lot of official chess rules, e.g. the touch-move rule, are just about not annoying your opponent.
3. It opens up ambiguity about what was actually intended. What if later the player tries to claim they really did mean a rook? What if a player accidentally turns one of their actual rooks upside down during the course of a game — is it still a rook, or are they trying to cheat by turning it into a queen? Etc.
4. It does not work with high-end electronic chessboards that automatically record moves (DGT).
5. Last but not least: there is absolutely no reason to allow this, because it’s impossible to imagine that at a serious tournament the arbiter wouldn’t be able to find an extra queen. And stopping the clock and asking for an arbiter, while still a bit distracting to others, is surely less distracting than starting a discussion with the opponent about whether it’s okay to use an overturned rook or any other random object as the queen.
1n6/PP1p4/n1p5/8/7q/5pbr/5k1p/7K w - - 0 1
https://www.chess.com/analysis/game/pgn/5WfasZuA6A/analysis
P.S. https://timkr.home.xs4all.nl/chess2/minor.htm contradicts my "Other reasons don't exist in play", assuming that the game that he analyzes actually happened, which is questionable.
White pawns on a7 and b7, king on h8. Black king on f2, bishop on g3, rook on h3, knights on a6 and b8, pawns on c6, d7, f3, and h2.
This position is a draw after a8=Q or axb8=Q but that is easily remedied by adding black pieces, e.g., a queen on h4.
A big part of chess is maximizing your own choices and freedom while restricting your opponents choices.
However, Level 2, making a decision harder for your opponent, might force them to spent more time thinking about the decision. If for some reason there is an imbalance of pondering, this might be beneficial. Suppose that you knew X position would be reached before your opponent, so you had more time to study it, you know what the correct piece to take is, whether a promoted rook, or a previously existing rook, but your opponent doesn't yet, and crowning to a queen will force your opponent into a move without a thought.
The computer will sometimes do this, more because of randomness than strategy, but it is probably always the case that if they underpromote, you should take, it's like a tell of theirs. Perhaps there is a case for nash equilibirum where you must sometimes offer an underpromotion in a scenario where a queen would have been marginally better such that underpromoting doesn't signal to your opponent that they should take the piece (whichever it may be, I'm a bit dizzy)
Very theoretical, but not impossible that underpromoting in such scenarios might be beneficial, that said, very theoretical.
For highly rated players, I think a resignation would occur before a promotion happens. So in general, promotions themselves are rare.
Now me, the only way I would win is to promote 3 pawns to 3 queens, and even then ... :)
What you might be overlooking is that often the player that promotes might have temporarily given up material in order to get the promotion so it is may just be restoring approximate equality.
Or it could be that the second player will also promote soon.
When playing someone low rated your opponent isn't good enough to think they can win unless there are less than 3 moves left so you may as well just play the rest of it out at that point. Even then, if you are in a simple (rook?) endgame if the low rated player makes a couple right moves you can assume they know the remaining moves so is it worth wasting your time to prove it?