Climbing - Revision history

Selinger: Terminology: prefer "pivot" to "break"

2025-05-26T02:24:52Z

Terminology: prefer "pivot" to "break"

Selinger: /* 3rd row ladder */ Added a case to scenario 2.

2024-04-27T12:53:36Z

‎3rd row ladder: Added a case to scenario 2.

Selinger: /* 2nd row ladder */ Added a scenario 7.

2022-09-21T23:36:10Z

‎2nd row ladder: Added a scenario 7.

Selinger: /* 2nd row ladder */ Added another climbing scenario.

2022-09-20T01:19:01Z

‎2nd row ladder: Added another climbing scenario.

Selinger: Added carrier to more scenarios.

2022-07-08T18:40:03Z

Added carrier to more scenarios.

Selinger: Started indicating carrier of the various scenarios.

2022-07-08T12:51:06Z

Started indicating carrier of the various scenarios.

Selinger: Added another 2nd row scenario

2022-07-08T12:43:56Z

Added another 2nd row scenario

Selinger: /* 3rd row ladder */ "Eric's move"

2021-09-06T00:48:16Z

‎3rd row ladder: "Eric's move"

Selinger: /* 3rd row ladder */ Minor edit

2021-09-05T15:03:26Z

‎3rd row ladder: Minor edit

Selinger: /* 3rd row ladder */ Fixed a link.

2021-09-05T14:36:04Z

‎3rd row ladder: Fixed a link.

@@ Line 20: / Line 20: @@
    contents="R i2 g7 g4 f8 f6 d7 c7 B h5 g8 e10 e8 e4 c10 c9"
    />
-Red starts a 3rd row ladder, then immediately breaks and climbs.
+Red starts a 3rd row ladder, then immediately pivots and climbs.
 <hexboard size="11x11"
    contents="R i2 g7 g4 f8 f6 d7 c7 B h5 g8 e10 e8 e4 c10 c9
@@ Line 34: / Line 34: @@
    contents="R h2 g3 g4 g5 f6 f7 f8 e9 B f3 h3 f5 h7 f9 d9 d11"
    />
-Red pushes the ladder, breaks, and zippers all the way to the opposite edge.
+Red pushes the ladder, pivots, and zippers all the way to the opposite edge.
 <hexboard size="11x11"
    contents="R h2 g3 g4 g5 f6 f7 f8 e9 B f3 h3 f5 h7 f9 d9 d11

@@ Line 136: / Line 136: @@
               S area(a1,a4,c4,f1,g1,g7,i7,i1) f4"
     />
 '''Scenario 3:''' If Red's 3rd row ladder comes with a [[Switchback#Switchback threat|switchback threat]], Red can play a switchback fork and climb to the 7th row, potentially bridging to a stone on the 9th row.

@@ Line 103: / Line 103: @@
    />
 Note that 5 is connected to the edge by [[double threat]]s marked "*", and 11 is connected to 9 and 5 by an [[interior_template#Interior_templates_from_edge_templates|interior ziggurat]].
 === 3rd row ladder ===

@@ Line 92: / Line 92: @@
              S area(a1,a6,b6,c5,d5,f3,f2,g1) area(h3,h8) g5"
    />
 === 3rd row ladder ===

@@ Line 69: / Line 69: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 a4 B a6 b6 c6 f5 R 1:e5 B 2:d5 R 3:f3 B 4:e3 R 5:g1"
+    contents="R a5 b5 c5 a4 B a6 b6 c6 f5 R 1:e5 B 2:d5 R 3:f3 B 4:e3 R 5:g1
     />
@@ Line 76: / Line 77: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 a6 b6 c6 B a7 b7 c7 h5 h6 R 1:e6 B 2:d6 R 3:e4 B 4:e5 R 5:g4 B 6:f4 R 7:g3 B 8:f3 R 9:h1"
+    contents="R a5 a6 b6 c6 B a7 b7 c7 h5 h6 R 1:e6 B 2:d6 R 3:e4 B 4:e5 R 5:g4 B 6:f4 R 7:g3 B 8:f3 R 9:h1
     />
@@ Line 99: / Line 101: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 B a6 b6 c6 d4 g5 R 1:e5 B 2:d5 R 3:f3"
+   visible="-a1--i1 a2--i2"
     />
@@ Line 106: / Line 110: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 B a6 b6 c6 g5 R 1:e5 B 2:d5 R 3:e4 B 4:d4 R 5:f2"
+   visible="-a1--i1"
     />
@@ Line 113: / Line 119: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 a4 B a6 b6 c6 g5 R 1:e5 B 2:d5 R 3:f3 B 4:e3 R 5:g1"
+    contents="R a5 b5 c5 a4 B a6 b6 c6 g5 R 1:e5 B 2:d5 R 3:f3 B 4:e3 R 5:g1
     />
@@ Line 128: / Line 135: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 B a6 b6 c7 d4 g5 R 1:c6 B 2:b7 R 3:e6 B 4:d6 R 5:e5 B 6:d5 R 7:f3"
+   visible="-a1--i1 a2--i2"
     />
 If Blue tries to yield earlier in scenarios 1–3, Red can play, respectively, scenarios 2–4 for 2nd row ladders to achieve the same outcome, and does not even require the 3rd-to-5th row [[Switchback#Switchback threat|switchback threat]]. For example, this is how scenario 3 plays out if Blue yields early:
@@ Line 134: / Line 143: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 B a6 b7 g5 R 1:b6 B 2:a7 R 3:d6 B 4:c6 R 5:d4 B 6:d5 R 7:f4 B 8:e4 R 9:f3 B 10:e3 R 11:g1"
+    contents="R a5 b5 B a6 b7 g5 R 1:b6 B 2:a7 R 3:d6 B 4:c6 R 5:d4 B 6:d5 R 7:f4 B 8:e4 R 9:f3 B 10:e3 R 11:g1
     />
 In scenario 4, if Blue yields any earlier than the second-to-last opportunity, Red can simply [[ladder handling|jump]] back to the 3rd row. The final and most interesting case is when Blue yields exactly at the second-to-last opportunity. In that case, after optionally invading Blue's bridge, the unique winning move is 3:

@@ Line 47: / Line 47: @@
 === 2nd row ladder ===
-'''Scenario 1:''' In this scenario, Red's space is limited. Red can climb to the 4th row, potentially [[bridge|bridging]] to a stone on the 6th row.
+'''Scenario 1:''' In this scenario, Red's space is limited. Red can climb to the 4th row, potentially [[bridge|bridging]] to a stone on the 6th row. The shaded cells are not needed for this and can be occupied by Blue.
 <hexboard size="6x8"
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 B a6 b6 c6 d4 f5 R 1:e5 B 2:d5 R 3:f3"
+   visible="-area(a1,a2,h2,h1)"
     />
@@ Line 58: / Line 60: @@
     coords="hide"
     edges="bottom"
-    contents="R a5 b5 c5 B a6 b6 c6 f5 R 1:e5 B 2:d5 R 3:e4 B 4:d4 R 5:f2"
+   visible="-a1--h1"
     />

← Older revision		Revision as of 12:43, 8 July 2022
Line 76:		Line 76:

	Of course, there are many variations of these basic scenarios, depending on what other pieces Red and Blue have on the board. But the four scenarios shown above are common, and are good starting points for planning more complex ladder escape forks.		Of course, there are many variations of these basic scenarios, depending on what other pieces Red and Blue have on the board. But the four scenarios shown above are common, and are good starting points for planning more complex ladder escape forks.
		+
		+	'''Scenario 5:''' If Red has enough space, Red can also yield to the 3rd row and then climb to the 6th row, even without a switchback threat. This is basically the same as Scenario 2 for 3rd row ladders below.
		+
		+	<hexboard size="8x8"
		+	edges="bottom"
		+	coords="hide"
		+	visible="-area(a1,a2,h2,h1)"
		+	contents="R h1 R 1:a7 B 2:a8 R 3:b7 B 4:b8 R 5:d6 B 6:d7 R 7:f6 B 8:e6 R 9:f5 B 10:e5 R 11:g3
		+	S area(a1,a6,b6,c5,d5,f3,f2,g1) area(h3,h8) g5"
		+	/>

	=== 3rd row ladder ===		=== 3rd row ladder ===

@@ Line 171: / Line 171: @@
              E a:c2 b:d2 c:b3 d:c3 e:a4 f:b4"
    />
-If Red plays there, Blue in theory no longer gets a 5th row ladder, nor any kind of ladder. If Blue plays at a or c, Red responds at b; if Blue plays at b, Red responds at a; if Blue plays at d, Red responds at e; if Blue plays at f, Red responds at d. This works in essentially the same way as blocking a 5th row ladder when there's not enough space under the ladder stone, see [[Theory_of_ladder_escapes#Definition_of_ladder_4|theory of ladder escapes]].
+Move 3 is named ''Eric's move'' after Eric Demer, who discovered it. If Red plays there, Blue in theory no longer gets a 5th row ladder, nor any kind of ladder. If Blue plays at a or c, Red responds at b; if Blue plays at b, Red responds at a; if Blue plays at d, Red responds at e; if Blue plays at f, Red responds at d. This works in essentially the same way as blocking a 5th row ladder when there's not enough space under the ladder stone; see [[Theory_of_ladder_escapes#Definition_of_ladder_4|theory of ladder escapes]].
 === 4th row and higher ladders ===