Editing Chess clock (section)

=== Fischer clock and related designs {{anchor|Fischer clock}} ===
[[Image:Olimpiada Bled Slovenija deska.jpg|thumb|Digital chess clock connected to a board that automatically senses when moves have been made.]]
Digital clocks and Internet gaming have spurred a wave of experimentation with more varied and complex time controls than the traditional standards. [[Time control]] is commonly used in modern chess in many different [[Time control#Methodology|methodologies]]. One particularly notable development, which has gained quite wide acceptance in chess, was proposed by former world champion [[Bobby Fischer]], who in 1988 filed for US patent 4,884,255 (awarded in 1989) for a new type of digital chess clock. Fischer's digital clock gave each player a fixed period of time at the start of the game and then added a small amount after each move.<ref name=":1">{{cite patent |country=US |number=4884255|status=patent |title=Digital chess clock |gdate= November 28, 1989|pridate=August 5, 1988|fdate= August 5, 1988|invent1= Fisher, Robert J.}}, filed August 5, 1988.</ref> Joseph Meshi called this "Accumulation" as it was a main feature of his patented Micromate-180 (US Patent 4,247,925 1978).<ref name=":0" />

The increment time control was first used in the privately organised [[Fischer–Spassky (1992 match)|1992 Fischer–Spassky match]], and quickly became popular in the wider chess world, being subsequently used in the [[FIDE World Chess Championship 1998]].<ref>[http://theweekinchess.com/html/twic161.html The Week in Chess 161], [[The Week in Chess]], 8-Dec-1997</ref> Nowadays most top level tournaments and tournaments outside the United States use Fischer's system. An increasing number of lower level tournaments in the US are also starting to use Fischer's system. Other aspects of Fischer's patent, such as a synthesized voice announcing how much time the players have, thus eliminating the need for them to keep looking at the clock, have not been adopted.<ref name=":1" />

On March 10, 1994, a patent application was filed by inventors Frank A. Camaratta Jr. of Huntsville, Alabama, and William Goichberg of Salisbury Mills, New York, for a game timer especially suitable for playing the game of chess, which employed a (simple) "delay" feature. The game timer provides, among other features, a user-definable delay between the time the activation button is pressed and the time that the activated clock actually begins to count down. United States Patent 5,420,830 was issued on May 10, 1995, and subsequently assigned to the United States Chess Federation by the inventors. As with the Fischer clock, the benefit of the delay clock is to reduce the likelihood that a player with positional or material superiority will lose a match solely because of the expiration of time on that player's time clock.<ref>{{Cite patent|number=US5420830A|title=Chess clock|gdate=1995-05-30|invent1=Jr|invent2=Goichberg|inventor1-first=Frank A. Camaratta|inventor2-first=William|url=https://patents.google.com/patent/US5420830/en}}</ref> In the United States, delay is still widely used, but increment is becoming more popular.<ref>{{Cite web |date=2021-09-28 |title=Rule Book Updates and Changes |url=https://new.uschess.org/rule-book-updates-and-changes |access-date=2023-07-15 |website=US Chess.org |language=en}}</ref>