A tactical way to improve ones position. Rules don’t exist but there are many practical examples especially in endgames.
ECHESSPEDIA
Quotes of the Day
Karpov, Kasparov, Korchnoi have absolutely destroyed chess by their immoral, unethical, prearranged games. These guys are really the lowest dogs around, and if people knew the truth about them, they would be held in more contempt than Ben Johnson, the runner, and they’re going to know the truth when I do this book!
Robert Fischer September, 1 1992
it would have been a debacle if Karjakin had become the 17th World Champion.
Garry Kasparov 2016
Preparation for a world championship was always an arms race, in previous times with books, then with seconds, today with computers.
Vishy Anand 2008
There is no room for gallantry in chess.
Irving Chernev
.If we compare Carlsen with Anand or me or someone else, by ten criteria, he will be stronger in eight of them.
Veselin Topalov 2015