Editing Two knights endgame (section)

==Checkmate in problems==
The possible checkmate on the edge of the board is the basis of some composed [[chess problem]]s, as well as variations of the checkmate with two knights against a pawn.

;Angos, 2005
{{Chess diagram small
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| Angos, 2005

|  |  |  |nl|  |  |kd|  
|  |nd|  |nl|  |  |  |  
|  |  |  |  |  |  |kl|  
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| White to move and mate in four 
}}
In this problem by Alex Angos, White checkmates in four moves:
:'''1. Ne6! Nd8'''
:'''2. Nf6+ Kh8'''
:'''3. Ng5 N'''–''any'' (Black is in [[zugzwang]] and any knight move must abandon the protection of the f7-square)
:'''4. Nf7#'''<ref>{{Harvcol|Angos|2005|p=46}}</ref>
{{clear}}

;;Berger, 1890
{{Chess diagram small
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| Berger, 1890

|  |  |  |  |nd|  |kd|  
|  |  |  |  |  |  |  |  
|  |  |  |nl|nl|  |kl|  
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| White to move and mate in four 
}}
A similar problem was composed by [[Johann Berger]] in 1890. The solution is:
:'''1. Nf7! Nd6'''
:'''2. Nh6+ Kh8'''
:'''3. Ng5'''
followed by 
:'''4. Ngf7#'''.<ref>{{Harvcol|Matanović|1993|pp=492–93}}</ref>
{{clear}}

;de Musset, 1849
{{Chess diagram small
| tright
| Alfred de Musset, 1849

|  |nd|  |  |kd|  |kl|  
|  |  |  |  |  |  |  |rl
|  |  |  |  |  |  |  |  
|  |  |  |  |nl|  |  |  
|  |  |  |  |  |  |nl|  
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| White to move and mate in three
}}
In this composition by [[Alfred de Musset]], White checkmates on the edge of the board in three moves with:
:'''1. Rd7 Nxd7'''
:'''2. Nc6 N'''–''any'' 
:'''3. Nf6#'''.<ref>{{Harvcol|Hooper|Whyld|1992}}</ref>
{{clear}}

;Sobolevsky, 1951
{{Chess diagram
| tright
| P. Sobolevsky, [[Shakhmaty v SSSR]], 1951

|  |  |  |  |  |  |  |  
|  |  |  |  |  |kd|  |nl
|  |  |  |  |  |bl|nl|  
|  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |kl
|  |  |  |  |  |  |nd|bd
|  |  |  |  |  |  |  |  

| White to move and win
}}
In this [[Endgame study|study]] composed by Sobolevsky, White wins by checkmating with two knights:

: '''1. Nh8+ Kg8'''
: '''2. Kxg2 Bf4'''
: '''3. Ng6 Bh6!'''
: '''4. Ng5 Bg7!'''
: '''5. Ne7+ Kh8'''
: '''6. Nf7+ Kh7'''
: '''7. Bh4! Bf6!'''
: '''8. Ng5+ Kh6'''<ref>There is no apparent win after 8...Kg7, based on analysis by [[Houdini (chess)|Houdini 2.0]]. Yet according to [[Nalimov tablebases]] - White does win by force.</ref>
: '''9. Ng8+ Kh5'''
: '''10. Nxf6+! Kxh4'''
: '''11. Nf3#'''<ref>{{Harvcol|Nunn|1981|p=6}}</ref>
{{clear}}

;Nadanian, 2009
{{Chess diagram
| tright
| Ashot Nadanian, [[ChessBase]], 2009<ref>{{cite web|url=http://www.chessbase.com/puzzle/christmas2009/chr09-05.htm|title=ChessBase Christmas Puzzles: A tale of seven knights|date=2009-12-29|publisher=ChessBase|access-date=6 February 2010}} Broken link</ref>

|  |  |  |  |  |  |  |rl
|  |  |  |nd|  |  |rd|  
|  |  |  |nl|  |  |nd|pd
|  |  |  |  |  |  |kd|pl
|  |  |  |nl|  |pd|  |  
|  |  |  |  |  |  |  |kl
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| White to move and win
}}
In this study composed by [[Ashot Nadanian]], White wins by checkmating with two knights:
: '''1. Rg8!! Rxg8'''
If 1...Re7, then 2.N6f5! Re1 3.Rxg6+ Kxh5 4.Rxh6+ Kg5 5.Nf3+ and White wins.
: '''2. Ne4+ Kxh5'''
: '''3. Ne6'''
and checkmate on the next move, due to [[zugzwang]]; two white knights deliver four different checkmates:<ref>{{cite web|url=http://www.chessbase.com/puzzle/christmas2009/chr09-sol1.htm|title=Solutions to 2009 Christmas Puzzles|date=2010-02-02|publisher=ChessBase|access-date=6 February 2010|url-status=dead|archive-url=https://web.archive.org/web/20100206203021/http://www.chessbase.com/puzzle/christmas2009/chr09-sol1.htm|archive-date=6 February 2010}} Broken link</ref> 
* '''3... R'''–''any'' '''4. Ng7#'''
* '''3... Nd'''–''any'' '''4. Nf6#'''
* '''3... Ng'''–''any'' '''4. Nf4#'''
* '''3... f3''' '''4. Ng3#'''
{{clear}}