Underpromotion - 2006/07/15 18:24Question: Is their any proper reason, ever, to underpromote to a R or a B? (e.g.. excluding just for wit, assumin proper play)
I have seen plenty of raesons for stealthily promoting to a N or a Q but never a R or a B. Obviously the check or forking advantage of a knight does not work in the case of a rook or a bishop because a queen can do which also.
However I can picture (fuzzily) something along the lines of piece placement, & by curiously underpromoting to a R or a B it might make the opponent attack another piece other than the promoted one, (eg. a knight captruring a rook in the cortner insead of a bihsop) A weird kind of sacrifice. Or where it's desperately needed to control a square where a bishop is stronger than a queen.
What i'm after is a setup where it'll be conceivably beneficial to underpromote to R or B.. ---------
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re:Underpromotion - 2006/07/15 19:33I recall a study by Rusinek in which white had to underpromote to a knight, a bishop, and then a rook in order to DRAW. The point was that in the case of the knight, promotion with check was necessary to avoid mate, and with the bishop and rook underpromotions, a queen would have proven TOO STRONG and would have had too many legal moves, again allowing checkmate ... whereas stalemate resulted with the underpromotions. I will look up this study and send it to you (am in the process of unpacking boxes, once I find it will give it to you)
Now on a lighter note, I remember an incident from when I was a teenager involving bishop underpromotion. An expert and an "A" player were paired in a local tournament. In this particular game the expert was frustrated as he had an extra Bishop and his opponent was still playing on. Expert simplified down to a position where he had a king, bishop, and pawn versus a lone king...and STILL the A player wouldn't resign! Expert nursed the pawn to the 7th rank, and in a gesture of contempt...underpromoted to a bishop. Only AFTER slamming the newly born bishop down on the last rank and hitting his clock did he realize...IT WAS ON THE SAME COLOR AS THE OTHER ONE.. ---------
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and now, white can not take a queen because of the possibility of 6 ... Re4+. The only way to win is for white to take a rook and then comes 6 ... Ra4 7 Kb3 and it is all over.
re:Underpromotion - 2006/07/15 20:46Of course, I should have written, "and now, white can not take a queen because of the possibility of 6 ... Rc4+.". ---------
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re:Underpromotion - 2006/07/15 21:23On http://www.xs4all.nl/~timkr/chess2/minor.htm you shall find neatly everything you want to know about this, and a lot more.. ---------
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re:Underpromotion - 2006/07/15 21:52The main reason for an underpromotion is to prevent stalemate. For example: wK: f6, wp:f7 bK: h7
If white were to play f7-f8Q it would be stalemate, f7-f8R would be mate on the next move.
See for more examples: http://www.xs4all.nl/~timkr/chess2/minor.htm. ---------
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Now if 8. b8Q (or b8 Ba6+ 9. Qb7 Ne4! 10. any Nd6#. 8. b8N Ne7 9. Kb7 Bg2+ 10. Ka7 Nc8+ 10. Ka6 Ba8: winning for black.
8. b8R!! Ba6+ 9. Rb7!
With a draw, as black must either stalemate white or allow the material balance to be equal.
Brilliant – it's next to impossible to create underpromotions necessary to DRAW, and to have three different such underpromotions in a gamelike position is just marvelous. This is my favorite study.. ---------
It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.
(iii) 3. Kb7? Rb1 4. Kc6 Rb6 5. Kd7 Rb7 6. Kc6 Ra7 7. h3 Bc3 8. Sc7 Rc7 9. Kc7 Ke7 and black wins (iv) 4. Kb7? Ra1(v) 5. Sc7 Ra7 6. Ka7 Bd4 and black wins (v) 4. ... Rb1? 5. Kc6 Ra1 6. Sc7 Ke7 7. Sd5 Kf7 8. Sc3 draw. ---------
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re:Underpromotion - 2006/07/15 22:54< your post comes here > 7k/5P2/8/5K2/8/8/8/eight w - - 0 1
in this position the quickewst victory comes with
1. Kf6 Kh7 2. f8=R Kh6 3.Rf8#
so people undertpromote in situations when they find it more benefecial than promotion to a queen as well.. ---------
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re:Underpromotion - 2006/07/15 23:39Usually avoiding stalemate would be the reason to promote to a rook or a bishop, but a knight also covers wich.. ---------
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Ba6+ 9. Qb7 Ne4! 10. any Nd6#. 8. b8N Ne7 9.