Viktor and Petra Korchnoi

A couple of recent reports from the mainstream chess press have their roots in a World Championship match from the 1970s. It's curious that all three title matches from the 1970s -- 1972, 1975 (unplayed), 1978 -- have achieved legendary status.

2021-03-23: 'The dirtiest chess match in history': Stean on Karpov-Korchnoi, 1978 (chess24.com; Colin McGourty)

The great Viktor Korchnoi, one of the strongest players never to become World Champion, would have turned 90 today. On the eve of that anniversary, the BBC dedicated an episode of the radio broadcast Witness History to the match that saw Viktor come within a win of claiming the World Championship title. The clash with Anatoly Karpov in Baguio City in the Philippines is described as "a surreal experience" by English Grandmaster Michael Stean, who turned 25 during the match and was working as a second for Viktor.

2021-03-19: Petra Korchnoi dies at 93 (chessbase.com; Frederic Friedel)

It is with great sadness that we announce the death of Petra Korchnoi – Petronella Leeuwerik before her marriage to the two-fold World Championship Challenger. She was a remarkable personality and a great friend, and will be sorely missed.

More than 20 years ago I used database techniques to compile a summary of the many themes that occurred in the match: 1978 Karpov - Korchnoi Title Match : Yogurt, Parapsychology, Ananda Marga, ... (m-w.com). That analysis still holds up today.