Difference between revisions of "Y puzzle solutions"

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==Standard Y puzzles==
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===Puzzle 1===
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<hexboard size="4x4"
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  edges="hide"
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  visible="area(a1,a4,d1)"
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  contents="R a1 B b1 R 1:a3 B 2:a2 R 3:c2"
 +
  />
 +
 +
Even this simple puzzle has a twist if you're new to Y. If Blue responds with b3, like below, Red's only winning move is b2:
 +
 +
<hexboard size="4x4"
 +
  edges="hide"
 +
  visible="area(a1,a4,d1)"
 +
  contents="R a1 B b1 R 1:a3 B 2:b3 R 3:b2"
 +
  />
 +
 +
===Puzzle 2===
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Blue b2 is the winning move. If Red 2. c2, then only Blue 3. c1 is winning.
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<hexboard size="5x5"
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  edges="hide"
 +
  visible="area(a1,a5,e1)"
 +
  contents="R b1 c3 B d2 1:b2 R 2:c2 B 3:c1 R 4:d1 B 5:a4"
 +
  />
 +
 +
In particular, Blue 3. a2?? is losing, since it crucially allows Red to connect to the top edge with tempo:
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 +
<hexboard size="5x5"
 +
  edges="hide"
 +
  visible="area(a1,a5,e1)"
 +
  contents="R b1 c3 B d2 1:b2 R 2:c2 B 3:a2 R 4:c1 B 5:a1 R 6:a4"
 +
  />
 +
 +
If Red plays 2. a3 instead, then Blue b3 is the only winning response:
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 +
<hexboard size="5x5"
 +
  edges="hide"
 +
  visible="area(a1,a5,e1)"
 +
  contents="R b1 c3 B d2 1:b2 R 2:a3 B 3:b3"
 +
  />
 +
 +
===Puzzle 3===
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<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R a2 c1 B b4 1:c2 R 2:d1 B 3:b2 R 4:b1 B 5:e2"
 +
  />
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 +
If Blue plays e2 too early, on move 3, it is losing due to Red 4. c3. If Blue 5. b2, then Red 6. d2. If Blue 5. d2, then Red 6. b3.
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 +
<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R a2 c1 B b4 1:c2 R 2:d1 B 3:e2 R 4:c3"
 +
  />
 +
 +
If Red plays 2. c3 instead, Blue's unique winning reply is 3. b2!
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 +
<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R a2 c1 B b4 1:c2 R 2:c3 B 3:b2"
 +
  />
 +
 +
===Puzzle 4===
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Red's initial stones resemble [[Edge template IV2d]], but in Y it's not an edge template since there are multiple edges to worry about. With 1. b3, Blue connects to either the top or the bottom-left edge (but Red may decide which one). After Red 2. c4, Blue 3. b4! is the only winning move. The carrier of Blue's win is shaded below; Blue can play a pairing strategy where if Red plays in a cell with a letter, Blue plays the other cell with the same letter.
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<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R c2 a4 B c3 1:b3 R 2:c4 B 3:b4 S b1 a3--c1 e1 d1--d3 a5 b5 E A:(b2 d2) B:(a3 a5) C:(d3 b5) D:(b1 c1) E:(d1 e1)"
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  />
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===Puzzle 5===
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If Blue plays 2. b2, then Red c1! is the unique winning reply, as shown below. If Blue 2. d1 instead, then c3 is the unique winning reply.
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<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R a1 e1 B b5 d2 R 1:c2 B 2:b2 R 3:c1"
 +
  />
 +
 +
Other moves don't work. For example, Red 1. b2 loses to c2:
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<hexboard size="6x6"
 +
  edges="hide"
 +
  visible="area(a1,a6,f1)"
 +
  contents="R a1 e1 B b5 d2 R 1:b2 B 2:c2"
 +
  />
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 +
===Puzzle 6===
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Blue's only winning move is 1. c4:
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<hexboard size="7x7"
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  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:c4 R 2:e2 B 3:b2"
 +
  />
 +
 +
It's instructive to see why other first moves fail. If Blue 1. c3, then Red d3! connects to the top-right corner with a two-stone [[corner template]] (d2 and d3):
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<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:c3 R 2:d3"
 +
  />
 +
 +
Here, Red 2. c1 doesn't work, since Blue's d4 stone will connect to the bottom-left edge:
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 +
<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:c3 R 2:c1 B 3:e2 R 4:d3 B 5:e3"
 +
  />
 +
 +
If Blue 1. b4, then Red 2. c4! is the unique winning reply. This is similar to Puzzle 4, where the intrusion into the pattern resembling [[Edge template IV2d]] is the only winning move.
 +
 +
<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:b4 R 2:c4"
 +
  />
 +
 +
If Blue 1. e2, then Red c4 is the unique winning reply:
 +
 +
<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:e2 R 2:c4 B 3:c5 R 4:d3 B 5:e3 R 6:a6"
 +
  />
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 +
Other Red replies to Blue e2 don't work. If Red 2. d3, then Blue c4 still wins:
 +
 +
<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:e2 R 2:d3 B 3:c4 R 4:e3 B 5:b2"
 +
  />
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 +
If Red 2. b5, then Blue 3. c3! wins due to this tricky line:
 +
 +
<hexboard size="7x7"
 +
  edges="hide"
 +
  visible="area(a1,a7,g1)"
 +
  contents="R a2 d1 d2 B d4 c2 1:e2 R 2:b5 B 3:c3 R 4:d3 B 5:c4 R 6:e3 B 7:b2"
 +
  />
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 +
==Bent-27 Y puzzle==
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[[Image:Y27puz_sol.gif]]
 
[[Image:Y27puz_sol.gif]]
  
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Back to the game of Y: [[Y]]
 
Back to the game of Y: [[Y]]
  
−
[[Category: Other games]]
+
[[Category:Y]]
 
[[category:Puzzle]]
 
[[category:Puzzle]]

Latest revision as of 23:22, 20 June 2026

Standard Y puzzles

Puzzle 1

abcd1234231

Even this simple puzzle has a twist if you're new to Y. If Blue responds with b3, like below, Red's only winning move is b2:

abcd1234312

Puzzle 2

Blue b2 is the winning move. If Red 2. c2, then only Blue 3. c1 is winning.

abcde1234534125

In particular, Blue 3. a2?? is losing, since it crucially allows Red to connect to the top edge with tempo:

abcde12345543126

If Red plays 2. a3 instead, then Blue b3 is the only winning response:

abcde12345123

Puzzle 3

abcdef12345642315

If Blue plays e2 too early, on move 3, it is losing due to Red 4. c3. If Blue 5. b2, then Red 6. d2. If Blue 5. d2, then Red 6. b3.

abcdef1234562134

If Red plays 2. c3 instead, Blue's unique winning reply is 3. b2!

abcdef123456312

Puzzle 4

Red's initial stones resemble Edge template IV2d, but in Y it's not an edge template since there are multiple edges to worry about. With 1. b3, Blue connects to either the top or the bottom-left edge (but Red may decide which one). After Red 2. c4, Blue 3. b4! is the only winning move. The carrier of Blue's win is shaded below; Blue can play a pairing strategy where if Red plays in a cell with a letter, Blue plays the other cell with the same letter.

abcdef123456DDEEAAB1C32BC

Puzzle 5

If Blue plays 2. b2, then Red c1! is the unique winning reply, as shown below. If Blue 2. d1 instead, then c3 is the unique winning reply.

abcdef123456321

Other moves don't work. For example, Red 1. b2 loses to c2:

abcdef12345612

Puzzle 6

Blue's only winning move is 1. c4:

abcdefg1234567321

It's instructive to see why other first moves fail. If Blue 1. c3, then Red d3! connects to the top-right corner with a two-stone corner template (d2 and d3):

abcdefg123456712

Here, Red 2. c1 doesn't work, since Blue's d4 stone will connect to the bottom-left edge:

abcdefg123456723145

If Blue 1. b4, then Red 2. c4! is the unique winning reply. This is similar to Puzzle 4, where the intrusion into the pattern resembling Edge template IV2d is the only winning move.

abcdefg123456712

If Blue 1. e2, then Red c4 is the unique winning reply:

abcdefg1234567145236

Other Red replies to Blue e2 don't work. If Red 2. d3, then Blue c4 still wins:

abcdefg123456751243

If Red 2. b5, then Blue 3. c3! wins due to this tricky line:

abcdefg12345677134652

Bent-27 Y puzzle

Y27puz sol.gif

The winning move is (a). The strongest reply is (b), after which Blue has to play (c) or (d). With correct play, all the nodes will become occupied.

Back to the game of Y: Y

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