Editing Threefold repetition (section)

===Kasparov vs. Deep Blue, 1997===
{{Chess diagram
|tright
|Kasparov vs. Deep Blue, 1997

|  |  |  |  |  |  |  |  
|pd|pd|  |  |  |  |pl|  
|  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  
|  |kd|pd|  |  |nl|  |  
|  |nd|  |  |rl|  |pl|  
|  |  |  |rd|  |  |  |  
|  |kl|  |  |  |  |  |  
|Position after 49...Kb4
}}

In the [[Deep Blue versus Garry Kasparov#1997 game 5|game]]<ref>{{cite web|url=http://www.chessgames.com/perl/chessgame?gid=1070916 |title=Kasparov vs. Deep Blue, 1997 |publisher=Chessgames.com |access-date=2020-07-03}}</ref> between [[Garry Kasparov]] and [[Deep Blue (chess computer)|Deep Blue]] in New York 1997, the game ended with a [[draw by agreement]], because after 49...Kb4 ({{em|diagram}}), if White plays 50.g8=Q, Black can force perpetual check and claim a draw after 54.Kb1 by threefold repetition:<ref>{{Harvcol|Hsu|2002|pp=251–52}}</ref>

:50...Rd1+
:51.Ka2, Kb2 or Kc2 Rd2+
:52.Kb1 (second time) Rd1+
:53.Ka2, Kb2 or Kc2 Rd2+
:54.Kb1 (third time)
{{clear}}