diff --git a/Advanced/Retrograde Analysis/chess-setup.tex b/Advanced/Retrograde Analysis/chess-setup.tex index a622a92..f2c0a25 100644 --- a/Advanced/Retrograde Analysis/chess-setup.tex +++ b/Advanced/Retrograde Analysis/chess-setup.tex @@ -17,25 +17,13 @@ \par } -\long\def\sixboards#1{ - \twoboards{#1} - \vfill - \twoboards{#1} - \vfill - \twoboards{#1} -} - \makeatletter \long\def\manyboards#1{ - \ifextras - \sixboards{#1} + \if@solutions + \twoboards{#1} \else - \if@solutions - \twoboards{#1} - \else - \twoboards{#1} - \twoboards{#1} - \fi + \twoboards{#1} + \twoboards{#1} \fi } diff --git a/Advanced/Retrograde Analysis/main.tex b/Advanced/Retrograde Analysis/main.tex index 120df4a..3b91fc9 100755 --- a/Advanced/Retrograde Analysis/main.tex +++ b/Advanced/Retrograde Analysis/main.tex @@ -1,83 +1,23 @@ % use [nosolutions] flag to hide solutions. % use [solutions] flag to show solutions. \documentclass[ - solutions + solutions, + shortwarning ]{../../resources/ormc_handout} \usepackage{../../resources/macros} - -% If true, this will be an "extras" handout -% (minimal, extra copies of chessboards.) -% -% This assumes nosolutions. -\newif\ifextras -\extrasfalse - - - -\ifextras - % Force-disable page numbers - % and leave bit more room for the six chessboards. - - \pagestyle{empty} - \geometry{ - bottom = 20mm, - footskip = 5mm, - } -\fi - - \usepackage{chessfss} \usepackage{chessboard} \usepackage{anyfontsize} % Silences some chess warnings \usepackage{afterpage} \usepackage[hang]{footmisc} - - - - -% Modify default tab positions for better stars in score decomposition -\TabPositions{1.2cm, 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, 8cm} - \input{chess-setup} -\input{stars} - -\makeatletter - -\@makeORMCbox{@hintlist} - {Score Decomposition:} - {black!12!white} - {black!80!white} - - -\ifextras - \excludecomment{hintlist} -\else -\newenvironment{hintlist}{ - \begin{@hintlist} -}{ - % Remove vspace from the last \hintcontent - \if@solutions\vspace{-2mm}\fi - \end{@hintlist} +\def\difficulty#1#2{ + \textbf{Difficulty:} \stars{#1}{#2} \par + \vspace{1mm} } -\fi - - -\long\def\hintcontent#1{ - \if@solutions - #1 \par - \vspace{2mm} - \fi -} - -\makeatother - - - - - \uptitlel{Advanced 2} \uptitler{Fall 2023} @@ -89,25 +29,16 @@ \begin{document} - \ifextras\else - \maketitle + \maketitle - \footnotetext[1]{ - Most of the easy problems in this handout are from \textit{The Chess Mysteries of Sherlock Holmes}.\\ - The rest are from \textit{The Chess Mysteries of the Arabian Knights}. - } + \footnotetext[1]{ + Most of the easy problems in this handout are from \textit{The Chess Mysteries of Sherlock Holmes}.\\ + The rest are from \textit{The Chess Mysteries of the Arabian Knights}. + } - \input{parts/00 rules} - \input{parts/01 intro} - \fi + \input{parts/01 intro} \input{parts/02 easy} \input{parts/03 medium} - %\input{parts/04 hard} - - - \ifextras - \sixboards{} - \vfill\pagebreak - \fi + \input{parts/04 hard} \end{document} \ No newline at end of file diff --git a/Advanced/Retrograde Analysis/parts/00 rules.tex b/Advanced/Retrograde Analysis/parts/00 rules.tex deleted file mode 100644 index a196467..0000000 --- a/Advanced/Retrograde Analysis/parts/00 rules.tex +++ /dev/null @@ -1,51 +0,0 @@ -\section{Rules} - -This handout contains a set of problems. You may solve them in any order. \par -Each is marked with a few stars, which you collect by presenting solutions. \par -An example is below. - -\vspace{4mm} - -\generic{Problem $0$:} -\onestars{4} - -This is a problem that has two parts. \par -If you solve the problem on your own, your team gets four points. \par - -\vspace{2mm} - -There are two ways you can ask for assistance: \par -\begin{itemize}[itemsep=1mm] - \item You may uncover a hint to a part for $\lceil 0.5 \times \text{that part's value} \rceil$ stars. \par - In this problem, the hints for both part 1 and 2 cost 1 star each. \par - These are always provided in order---you must solve or uncover part 1 to get a hint for part 2. - - \item You may also ask an instructor to check the work you have thus far. \par - By doing this, you will earn stars for all parts you no longer need a hint for. -\end{itemize} - - -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{3} \par - \hintcontent{ - This is a hint. Only instructors see this. - } - - Part 2: \tab\threestars{1}{2}{1} \par - \hintcontent{ - This is another hint. - } - - \vspace{2mm} - Done: \tab\threestars{3}{1}{0} -\end{hintlist} - -\vspace{1cm} - -Each \say{part} corresponds to one hint in the instructor's handout. \par -\say{Done} is not a hint, it is simply a bonus for completing the problem. - - - -\vfill -\pagebreak \ No newline at end of file diff --git a/Advanced/Retrograde Analysis/parts/01 intro.tex b/Advanced/Retrograde Analysis/parts/01 intro.tex index cd14250..78cd5d6 100644 --- a/Advanced/Retrograde Analysis/parts/01 intro.tex +++ b/Advanced/Retrograde Analysis/parts/01 intro.tex @@ -137,22 +137,5 @@ A king and rook can \textit{castle} under the following conditions: \end{minipage} \par -\vfill - -\generic{General Strategies:} -As you solve problems, keep the following in mind. \par -You may want to return to this list if you get stuck. - -\begin{itemize} - \item What was the last move? (By black or white) - - \item Were there any promotions? The implication may be indirect: \par - if White needs a third bishop, there was a promotion. \par - \note{Promotions often resolve seemingly impossible situations.} - - \item Do not assume that Black and White play well. - You may only assume they play \textit{correctly}. -\end{itemize} - \vfill \pagebreak \ No newline at end of file diff --git a/Advanced/Retrograde Analysis/parts/02 easy.tex b/Advanced/Retrograde Analysis/parts/02 easy.tex index d0a658f..d3f5263 100644 --- a/Advanced/Retrograde Analysis/parts/02 easy.tex +++ b/Advanced/Retrograde Analysis/parts/02 easy.tex @@ -1,21 +1,16 @@ -\ifextras\else - \section{Simple problems} -\fi +\section{Simple problems} % Sherlock, A little exercise \problem{A little exercise} -%\difficulty{1}{5} -\onestars{3} +\difficulty{1}{5} + Black has just moved in the game below. White started on the south side of the board.\par What was Black's last move, and what was White's last move? \par - -\ifextras\else \note[Note]{ The boards below are identical copies. Scribble to your heart's content.\\ There a few empty boards at the end of this handout as well. } -\fi \manyboards{ ka8,Kc8, @@ -23,21 +18,6 @@ What was Black's last move, and what was White's last move? \par Bg1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{2} \par - \hintcontent{ - What was Black's last move? What did White do to make this happen? - } - - Part 2: \tab\threestars{1}{1}{1} \par - \hintcontent{ - White uncovered a check. What piece did Black capture? - } - - \vspace{2mm} - Done: \tab\threestars{2}{1}{0} -\end{hintlist} - \begin{solution} It's pretty clear that Black just moved out of check from A7. @@ -73,8 +53,8 @@ What was Black's last move, and what was White's last move? \par % Sherlock, Which color? \problem{Which color?} -%\difficulty{2}{5} -\onestars{4} +\difficulty{2}{5} + In the game below, no pieces have moved from a black square to a white square, or from a white square to a black square. There is a pawn at G3. What color is it? \par As before, White started on the bottom of the board. @@ -86,23 +66,6 @@ As before, White started on the bottom of the board. Pd2,Pf2 } - -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{3} \par - \hintcontent{ - How did the white king get off E1? It must have castled! - } - - Part 2: \tab\threestars{1}{1}{2} \par - \hintcontent{ - It castled kingside (how do we know?) \par - Now, how did it get off G1? - } - - \vspace{2mm} - Done: \tab\threestars{2}{2}{0} -\end{hintlist} - \begin{solution} The white king is the key to this solution. How did it get off of E1? \par It must have castled kingside---castling queenside would move a rook from black to white. @@ -131,8 +94,7 @@ As before, White started on the bottom of the board. % Arabian Knights 2 \problem{Invisible, but not invincible} -%\difficulty{2}{5} -\onestars{4} +\difficulty{2}{5} The black king has turned himself invisible. Unfortunately, his position is hopeless. \par Mate the king in one move. \par @@ -143,14 +105,6 @@ Mate the king in one move. \par Pa6,Rc6 } -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{3} \par - \hintcontent{Don't forget about promotion.} - - \vspace{2mm} - Done: \tab\threestars{1}{3}{0} -\end{hintlist} - \begin{solution} Since it is White's move, Black cannot be in check. \par So, either White is in check or the black king is on C8. \par @@ -173,8 +127,8 @@ Mate the king in one move. \par % Sherlock, a question of survival \problem{An empty board} -%\difficulty{2}{5} -\onestars{4} +\difficulty{2}{5} + In the game below, no pieces have moved from a black square to a white square, or from a white square to a black square. There is one more piece on the board, which isn't shown. What color square does it stand on? \par @@ -184,16 +138,6 @@ There is one more piece on the board, which isn't shown. What color square does Ke1 } - -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{3} \par - \hintcontent{Which piece performed the last capture on a black square?} - - \vspace{2mm} - Done: \tab\threestars{1}{3}{0} -\end{hintlist} - - \begin{solution} Which piece performed the last capture on a black square? It couldn't have been a white pawn, which haven't moved. @@ -211,8 +155,8 @@ There is one more piece on the board, which isn't shown. What color square does % Sherlock, another monochromatic \problem{The knight's grave} -%\difficulty{3}{5} -\onestars{4} +\difficulty{3}{5} + In the game below, no pieces have moved from a black square to a white square, or from a white square to a black square. The white king has made less than fourteen moves. \par Use this information to show that a pawn was promoted. \par @@ -223,15 +167,6 @@ Use this information to show that a pawn was promoted. \par Ke1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{3} \par - \hintcontent{ - Who took the knights? Only one of them is interesting---most are easy to account for. - } - \vspace{2mm} - Done: \tab\threestars{1}{3}{0} -\end{hintlist} - \begin{solution} Knights always move to a different colored square, so all four missing knights must have been captured on their home square. What pieces captured them? @@ -256,8 +191,8 @@ Use this information to show that a pawn was promoted. \par % Arabian Knights, intro (given with solution) \problem{Promotion?} -%\difficulty{2}{5} -\onestars{6} +\difficulty{2}{5} + It is White's move. Have there been any promotions this game? \par @@ -266,18 +201,6 @@ It is White's move. Have there been any promotions this game? \par Bc1,Kd1,Rh1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{4}{2} \par - \hintcontent{ - The black king must have moved from F1. (Why not G1?) \par - This would be impossible if something hadn't blocked check from the white rook. - } - - \vspace{2mm} - Done: \tab\threestars{4}{2}{0} -\end{hintlist} - - \begin{solution} Since it is White's move, Black has just moved his king. Where did he move it from? @@ -303,8 +226,7 @@ It is White's move. Have there been any promotions this game? \par % Sherlock Holmes, two bagatelles (1) \problem{Whodunit} -%\difficulty{2}{5} -\onestars{6} +\difficulty{2}{5} It is Black's move. Can Black castle? \par \hint{Remember the rules of chess: you may not castle if you've moved your rook.} @@ -318,18 +240,6 @@ It is Black's move. Can Black castle? \par Bc1,Qd1,Ke1,Bf1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{4}{2} \par - \hintcontent{ - Black captured a knight on his last move. \par - Why do we know this, and how did he do it? - } - - \vspace{2mm} - Done: \tab\threestars{4}{2}{0} -\end{hintlist} - - \begin{solution} White's last move was with the pawn. \par Black's last move must have been to capture the white piece which moved before that. @@ -365,8 +275,7 @@ It is Black's move. Can Black castle? \par % Sherlock Holmes, two bagatelles (2) \problem{Castle contradiction} -%\difficulty{2}{5} -\startimes{7} +\difficulty{2}{5} Neither Black nor White captured a piece on their last move. \par It is Black's move. Can he castle? \par @@ -381,19 +290,6 @@ It is Black's move. Can he castle? \par } -\begin{hintlist} - Part 1: \tab\threestars{0}{4}{3} \par - \hintcontent{ - If White moved his king, Black cannot castle. Why? \par - That's the simple case. The other option: White castled. What did Black do before that? - (Also, there was a promotion in this case.) - } - - \vspace{2mm} - Done: \tab\threestars{4}{3}{0} -\end{hintlist} - - \begin{solution} If White's last move was with the king, then the black rook moved to check him and Black can't castle. @@ -428,8 +324,7 @@ It is Black's move. Can he castle? \par % Arabian Knights, intro (given with solution) \problem{A matter of order} -%\difficulty{3}{5} -\startimes{8} +\difficulty{3}{5} A black bishop captured a White piece earlier in this game. \par Which bishop was it, and what did it capture? \par @@ -446,37 +341,6 @@ Which bishop was it, and what did it capture? \par Kc1,Rd1,Rh1 } - -\begin{hintlist} - Part 1: \tab\threestars{0}{1}{7} \par - \hintcontent{ - \begin{itemize} - \item How many pieces are missing? Where were the missing ones captured? - \item How did those pieces get to the place they were captured? - \end{itemize} - } - - Part 2: \tab\threestars{1}{2}{5} \par - \hintcontent{ - \begin{itemize} - \item The pawn on C3 came from D2, capturing a black rook. - \item The black rook it captured couldn't have moved there before... - \end{itemize} - } - - Part 3: \tab\threestars{3}{3}{2} \par - \hintcontent{ - \begin{itemize} - \item ...the black pawn on G7 captured a white piece on H6. - \item What else is missing? - \end{itemize} - } - - \vspace{2mm} - Done: \tab\threestars{6}{2}{0} -\end{hintlist} - - \begin{solution} First, notice that the pawn on C3 came from D2 by capturing a piece. \par This must have been a black rook, which is the only missing black piece. diff --git a/Advanced/Retrograde Analysis/parts/03 medium.tex b/Advanced/Retrograde Analysis/parts/03 medium.tex index f0f9907..3bf78ca 100644 --- a/Advanced/Retrograde Analysis/parts/03 medium.tex +++ b/Advanced/Retrograde Analysis/parts/03 medium.tex @@ -1,11 +1,9 @@ -\ifextras\else - \section{Slightly harder problems} -\fi +\section{Slightly harder problems} + % Sherlock, A matter of direction \problem{A matter of direction} -%\difficulty{3}{5} -\onestars{4} +\difficulty{3}{5} The results of a game of chess are shown below. \par Did White start on the north or south side of the board? \par @@ -18,15 +16,6 @@ Did White start on the north or south side of the board? \par Bh1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{2}{2} \par - \hintcontent{ - The bishop on H1 is important. How did White deliver this check? - } - \vspace{2mm} - Done: \tab\threestars{2}{2}{0} -\end{hintlist} - \begin{solution} Let us first find White's last move. It wasn't with the pawns on D4 and E5, since Black wouldn't have a move before that. (Note the double-check on A7). @@ -57,8 +46,8 @@ Did White start on the north or south side of the board? \par % Arabian Knights 1 \problem{Where is the king?} -%\difficulty{3}{5} -\startimes{8} +\difficulty{3}{5} + The white king has again become invisible. Find him. \par \hint{White started on the bottom. En passant.} \par @@ -70,31 +59,6 @@ The white king has again become invisible. Find him. \par } -\begin{hintlist} - Part 1: \tab\threestars{0}{2}{6} \par - \hintcontent{ - Either the white king is on B3, or Black is in check. \par - First, show that the latter implies the former. - } - - Part 2: \tab\threestars{2}{2}{4} \par - \hintcontent{ - Moving back in time, you'll need to add two pieces to the board (not counting the king). \par - They have been captured! - } - - \vspace{2mm} - Done: \tab\threestars{4}{4}{0} -\end{hintlist} - - -\makeatletter -\if@solutions - \vfill - \pagebreak -\fi -\makeatother - \begin{solution} Looking at the board, we see that the white king is on B3 or Black is in check. @@ -153,8 +117,8 @@ The white king has again become invisible. Find him. \par % Arabian Knights, intro (given with solution) \problem{Double-checks} -%\difficulty{3}{5} -\startimes{10} +\difficulty{3}{5} + White to move. Which side of the board did each color start on? \par \hint{What was Black's last move? } @@ -165,18 +129,6 @@ White to move. Which side of the board did each color start on? \par Nd1,kf1,Kh1 } -\begin{hintlist} - Part 1: \tab\threestars{0}{6}{3} \par - \hintcontent{ - Double-checks make all positions seem impossible... \par - Try E1 and F2 anyway. Can you add pieces to make it make sense? \par - Don't forget about promotion. - } - - \vspace{2mm} - Done: \tab\threestars{6}{3}{0} -\end{hintlist} - \begin{solution} Black's last move was from F2, where his king was in double-check from both a rook and a knight. How did this happen? @@ -217,13 +169,12 @@ White to move. Which side of the board did each color start on? \par % Arabian Knights 4 \problem{A missing piece} -%\difficulty{4}{5} -\startimes{20} +\difficulty{4}{5} + There is a piece at G4, marked with a $\odot$. \par What is it, and what is its color? \par - \manyboards{ ra8,ke8,rh8, pc7,pd7, @@ -236,44 +187,6 @@ What is it, and what is its color? \par } -\begin{hintlist} - Part 1: \tab\threestars{0}{2}{18} \par - \hintcontent{ - What color is the missing piece? Count captures.\par - Look at the region bounded by A1 and B3. How did the bishop get there? - } - - Part 2: \tab\threestars{2}{2}{16} \par - \hintcontent{ - What was White's last move? \par - What does this tell us about White's king? - } - - Part 3: \tab\threestars{4}{4}{12} \par - \hintcontent{ - Now, look at the region bounded by G1 and H3. \par - In Part 1, we found that all of White's pieces were captured---including the H1 rook. \par - How did it get off its home square to be captured? \par - What does this tell us about the bishop on H1? - } - - Part 4: \tab\threestars{8}{3}{9} \par - \hintcontent{ - The black bishop on H2 must have been promoted on G1. \par - Which pawn was it, and how did it get there? (Remember, we counted captures in Part 1). \par - In what order did the cross capture by the G1 and H1 pawns occur? - } - - Part 5: \tab\threestars{11}{2}{7} \par - \hintcontent{ - Which black pieces are still missing? \par - Remember that White cannot castle through check. - } - - \vspace{2mm} - Done: \tab\threestars{13}{7}{0} -\end{hintlist} - \makeatletter \if@solutions \vfill @@ -281,6 +194,7 @@ What is it, and what is its color? \par \fi \makeatother + \begin{solution} \textbf{Part 1:} diff --git a/Advanced/Retrograde Analysis/stars.tex b/Advanced/Retrograde Analysis/stars.tex index 80b9612..8b13789 100644 --- a/Advanced/Retrograde Analysis/stars.tex +++ b/Advanced/Retrograde Analysis/stars.tex @@ -1,40 +1 @@ -\ifextras - \def\nstars#1#2{} - \def\startimes#1{} - \def\onestars#1{} - \def\threestars#1#2#3{} -\else - \def\nstars#1#2{% - \ifnum #2 > 0% - \def\starcolor{\color{#1}}% - \count255=1% - \loop{% - \starcolor $\bigstar$% - }% - \ifnum \count255 < #2% - \advance\count255 by 1% - \repeat% - \fi% - } - - - \def\startimes#1{ - {\color{ogrape} $\bigstar \times #1$} - } - - \def\onestars#1{ - \nstars{ogrape}{#1} - } - - \def\threestars#1#2#3{ - \nstars{white}{#1}\nstars{ogrape}{#2}\nstars{white}{#3} - } - - - % Not used, commented out. - \def\difficulty#1#2{ - \textbf{Difficulty:} \stars{#1}{#2} \par - \vspace{1mm} - } -\fi