Editing Checkmate (section)

==Rare checkmates==
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In some rare positions it is possible to force checkmate with a king and knight versus a king and pawn.

===Stamma's mate===
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In the diagram showing Stamma's mate (named for [[Philipp Stamma]]), White to move wins:<ref>{{harvnb|Emms|2004|p=122}}</ref>
: '''1. Nb4+ Ka1'''
: '''2. Kc1 a2'''
: '''3. Nc2#'''

White also wins if Black is to move first:
: '''1... Ka1'''
: '''2. Nc1 a2'''
: '''3. Nb3#'''

{{Clear}}
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This checkmate occurred in [[Jesús Nogueiras]]–[[Maikel Gongora]], 2001 [[Cuban Chess Championship|Cuban Championship]]<ref>{{cite web |url=http://www.chessgames.com/perl/chessgame?gid=1218922 |title=Nogueiras vs. Gongora, Las Tunas 2001 |website=[[Chessgames.com]] |date=2005-02-08 |access-date=2012-06-18 }}</ref> (see diagram), which proceeded:

: '''81. Kc2 Ka1'''
: '''82. Nc5 Ka2'''
If 82...a2 then 83.Nb3#.
: '''83. Nd3'''
Reaching the position in the first diagram, with Black to move.
: '''83... Ka1'''
: '''84. Nc1 {{chessAN|1–0}}'''
Black [[resign (chess)|resigned]] here; play would have continued 84...a2 85.Nb3#.<ref>{{harvnb|Snape|2003|p=55}}</ref>
{{Clear}}

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A similar position with the knight on d2 is more than 500 years old, identified as "Partito n. 23" by Luca Pacioli, in his ''MS De ludo scachorum'' (Latin for "The game of chess"), dated 1498 and recently reprinted (Gli scacchi) by Aboca Museum Edizioni.

:'''1. Nf3 Ka1'''
:'''2. Nd4 Ka2'''
:'''3. Ne2 Ka1'''
:'''4. Nc1 a2'''
:'''5. Nb3#'''
{{Clear}}

===Unusual mates===
There are also positions in which a king and a knight can checkmate a king and a bishop, knight, or rook; or a king and a bishop can checkmate a king with a bishop on the other color of squares or with a knight, but the checkmate cannot be forced if there is no other material on the board (see the diagrams for some examples).<ref name=pand09p63>{{harvnb|Pandolfini|2009|p=63}}</ref> Nevertheless, it keeps these {{chessgloss|material}} combinations from being ruled a [[draw (chess)|draw]] because of "insufficient mating material" or "impossibility of checkmate" under the [[FIDE]] [[rules of chess]]. The [[U.S. Chess Federation]] rules are different. In a typical position with a {{chessgloss|minor piece}} versus a minor piece, a player would be able to claim a draw if they have a limited amount of time left.<ref>{{harvnb|Just|Burg|2003|pp=49, 291}}</ref>
{{Clear}}

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{{Clear}}

===Two and three knights===
;Two knights
{{Main|Two knights endgame}}
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|Checkmate cannot be forced. Here, ...Ka8?? allows checkmate (Nbc7#), but ...Kc8 avoids it.
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{{Clear}}

It is impossible to ''force'' checkmate with a king and two knights, although checkmate positions are possible (see the first diagram). In the second diagram, if Black plays 1...Ka8{{chesspunc|??}} White can checkmate with 2.Nbc7#, but Black can play 1...Kc8 and escape the threat. The defender's task is easy – they simply have to avoid moving into a position in which they can be checkmated on the next move, and they always have another move available in such situations.<ref>{{harvnb|Speelman|Tisdall|Wade|1993|p=11}}</ref>

In the third diagram, one knight is guarding c1, leaving the other knight to try to checkmate. After 1.Ndc3+ Ka1, White needs to get the knight on e2 to c2. But if White plays 2.Nd4, Black is [[stalemate]]d.<ref name=pand09p59>{{harvnb|Pandolfini|2009|p=59}}</ref>

Under some circumstances, two knights and a king can force checkmate against a king and pawn (or rarely more pawns). The winning plan, quite difficult to execute in practice, is to blockade the enemy pawn(s) with one of the knights, maneuver the enemy king into a stalemated position, then bring the other knight over to checkmate.<ref name=pand09p59 /> (See [[Two knights endgame]].)

;Three knights
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Three knights and a king can force checkmate against a lone king within twenty moves (assuming that the lone king cannot quickly win a knight).<ref>{{harvnb|Fine|1941|pp=5–6}}</ref>  These situations are generally only seen in [[chess problems]], since at least one of the knights must be a [[promotion (chess)|promoted piece]], and there is rarely a reason to promote a pawn to a piece other than a queen (see [[underpromotion]]).