# Tag Info

### A challenge for rookies

J, 29 27 24 23 bytes ' .*xR'{~*/~,0,.~1+=i.8 Try it online! My initial observation was that the output is essentially a row-wise function table of the 8x8 identity ...
• 33.4k

### How many Wazirs can be placed on an N×N Chessboard?

Whitespace, 45 bytes Try it online! By the way, here ...
• 68.7k

### Knight on the Rim is Grim

Python 2, 35 bytes lambda x,y:50/(8+x*x/7-x+y*y/7-y)-4 Try it online! Python 2, 39 bytes ...
• 145k

### Totally Blind Chess

Just Everything Generates a list of every possibly legal move, shuffles it, then cycles through it repeatedly. Since there are only 1792 possibly legal moves, this will never forfeit due to the 2000-...
• 1,226

### The Path Of The Wildebeest

JavaScript (Node.js),  191 ... 166  164 bytes Saved 2 bytes thanks to @grimy. Returns the $N$th term. ...
• 192k

### Totally Blind Chess

Zombie March Slowly walks all its pieces forward across the board, in a random order (but favoring pawns). The first 5 moves sent specifically counter the scholar's mate. ...
• 1,226

### The Knight's Dialer

JavaScript (ES6),  62 61  60 bytes My Python port, ported back to JS. :-p f=(n,k,o=k%2)=>n--?k-5&&(2-o)*f(n,!k*3-~o)+(k&5&&f(n,o*4)):1 Try ...
• 192k

### N-movers: How much of the infinite board can I reach?

JavaScript (Node.js), 144 138 125 74 73 70 bytes f=(x,n=2,c=0)=>x%n?x-!c?f(x,n+1)/(n%4>2?n/=~c&1:n%4)**c:1:f(x/n,n,c+1) Try it online! -4 byte thanks @...
• 6,208

Python 2, 52 bytes f=lambda n:n<6orn%100in'18349276167294381'*f(n/10) Checks that any two consecutive digits are in the string ...
• 145k

### Knight on the Rim is Grim

MATL, 17 14 13 12 bytes Thanks to @Neil for 1 byte off! 8:HZ^ZP5X^=s Input is 1-based. Try it online! Explanation This computes the Euclidean distance from the ...
• 104k

### Totally Blind Chess

Scholar ...
• 22.2k
Accepted

Jelly, 19 15 14 bytes Doȷ’d3ạ2\P€=2P Try it online! or verify all test cases. How it works ...
• 210k

### Convert a Forsyth-Edwards Notation string to ASCII art

Retina, 13 bytes \d $* / ¶ | Try it online! Explanation The first part (note the trailing space): \d$* is to convert ...
• 29k

### How many Wazirs can be placed on an N×N Chessboard?

Oasis, 3 bytes k>v Try it online! square - increment - integer halve
• 49.7k

### Identify a "reverse checkers" position

Python, 34 bytes lambda p:{*p[::2]}<{*p}>{*p[1::2]} Attempt This Online! Accepts a single string. Works for any distinct 4 characters for empty,black,white,newline. How? Uses the fact that ...
• 16.7k

### Knight to fork!

Python 2, 129 bytes def f(a):x,p,y,q,z,r=map(ord,a);x-=z;y-=z;p-=r;q-=r;u=x*x+p*p;v=y*y+q*q;w=x*q-y*p<<1;return chr((u*q-v*p)/w+z)+chr((v*x-u*y)/w+r) Try it ...
• 34.7k
Accepted

### Output all the white or black squares of a chessboard

Pyth, 22 21 bytes -1 byte by @Sp3000 fn%Chz3%sCMT2sM*<G8S8 Under the function %Chz3, dark...
• 21.5k

### Knight on the Rim is Grim

Mathematica 63 43 bytes With 20 bytes saved thanks to suggestions by Martin Ender! EdgeCount[8~KnightTourGraph~8,#+1+8#2/<->_]& The above finds the ...
• 25.3k

### Totally Blind Chess

Blunt Instrument v2 There was a severe bug in the previous implementation that caused my bot to occasionally move pieces away from the enemy king. Given that the king is the most important piece, ...
• 1,873
Accepted

### Totally Blind Chess

Pokey Opens with the knight-based variant of the Scholar's Mate (a 5-move checkmate). If this fails, it presses the attempt a little farther, with a sequence of moves that hardcounters Prickly. The ...
• 1,226

### Generate All 8 Knight's Moves

Wolfram Language (Mathematica), 25 bytes Solve[x^2y^2==4,Integers] Try it online! Outputs a list of {x -> x, y -> y}s.
• 20.4k

### Is it a plausible chess move?

Octave, 24 bytes @(a,b)imag((a-b)**4)<28i Try it online! Takes two complex numbers as inputs. How? Port of @xnor's python answer plus a trick or two by myself. ...
• 16.7k

### Is it a plausible chess move?

Python 2, 29 bytes lambda a,b:abs((a-b)**4%1)<28 Try it online! Based on @xnor's answer. Takes two complex numbers as input. Python 2, 42 bytes ...
• 16.7k

### Mutually Attacking Queens

Python 2, 105 bytes lambda b:sum(b[i+d::d][:(8,7-i%8,i%8)[d%8%5]].find('1')*int(c)>0for i,c in enumerate(b)for d in[1,7,8,9]) Try it online! Explanation We ...
• 68.7k

• 197k

### A knight's graph on an N-by-N board

MATL, 17 16 bytes t&l[2K0]B2:&ZvZ+ Try it online! (-1 byte thanks to @Luis Mendo.) The main part of the code is creating a matrix $K$ for ...
• 6,612

### Greedy queens sequence

APL (Dyalog Unicode), 38 bytes 1+{⍵,⊃⍸|⊃×/×(⌽⍳≢⍵)(⊢×+×-)⍵-⊂⍳3×≢⍵}⍣⎕⊢⍬ Try it online! Kinda port of tsh's JS and Python answers. They actually need some ...
• 75.9k

### Knight to fork!

Vyxal, 50 21 19 bytes ƛk-:dẊ:RJ\$Cv+C;Þf∆M Try it Online! One of the programs ever written. Luckily, there's no enpassant with horseys, so there's no bricks needed. ...
• 33.2k