Spassky qualified for this match from the Spassky - Hort Candidates Quarterfinal (1977) that ended in Iceland in April. Portisch qualified from the Portisch - Larsen Candidates Quarterfinal (1977) that ended in the Netherlands in March. The other semifinal match was the Korchnoi - Polugaevsky Candidates Semifinal (1977). Each match was of 16 games, and the first to 8,5 points would be the winner. If after 16 games there was no winner, two more games would be played. If there still was no winner, then two more games would be played, and this process would be repeated until there was a winner. (1, 2) The matches were held in order to select a challenger for Anatoly Karpov, the World Champion.
Partly based on the Geneva (1977) success, the Spassky-Portisch encounter was also held in Hôtel Méditerranée and organized by the Swiss Chess Federation. The organizers had put up a prize fund of 25,000 Swiss francs, five-eighths to the winner and three-eights to the loser. (1) Spassky started with his wife Marina as official second. (3) He had played no games after the quarterfinal. Portisch had Gyozo Forintos as his only second. (2) After the quarterfinal, Portisch had played seven games in the European Team Championship (Moscow 13-24 April). Game 1 started at 2 pm, and so did most other games (as reported in Journal de Genève). FIDE (World Chess Federation) had appointed Harry Golombek as Chief Arbiter. (1, 4) His assistant was Gerry Walsh. (5)
The players (picture and video): https://web.archive.org/web/2015041... and http://www.aparchive.com/metadata/S...
The playing room rarely had more than about 60 or 70 spectators at any one time. A grave calm and silence generally prevailed during playing time. This was only occasionally broken by a small group of two or three spectators who, in their enthusiasm, committed the double sin of discussing the position loudly. Fortunately they were invariably weak players, so that the conversation, which was rapidly suppressed by an arbiter or a steward, was of no help to either player. (6) After 11 games the players had 5.5 points each. Portisch had twice taken the lead, but Spassky equalized, each time after he had requested a postponement (of Games 5 and 9). (7, 8) Spassky played Game 9 in his old world championship style and got tumultous applause from the spectators. (9) Game 11 (scheduled for 31 July) was postponed till 5 August on Portisch's request. (10) He asked for a double time-out for a trip to Hungary. (11) The reason was not clear but it was put down to homesickness, caused by constantly playing abroad. (12) At the request of Spassky, following the example of the other quarterfinal in Évian-les-Bains, the organizers spent the available time installing a new ringtone to signal the players whose turn it was to play. However, Golombek banned the installation based on FIDE regulations. According to him, no one, let alone the referee himself, had the right to help the players during the game. In fact, the system in use in Evian was irregular. (3)
On the day after Game 11 (a draw), former world champion Vasily Smyslov arrived. Spassky said that "my official second is and will remain my wife Marina", and he was "very happy to see Smyslov in Geneva". (3, 13) Game 12 (scheduled for 7 August) was postponed till 9 August, on Spassky's third and last available time-out. (14) On 9 August, as late as at 11:15 am, Portisch also asked for his third postponement till 12 August. This was supposedly a psychological move. He was reportedly not actually sick, but wanted an equal number of postponements for both players. (15) In Game 12, Portisch looked certain to win by move 50, but Spassky salvaged the draw. Portisch said he "threw victory away". (16)
Smyslov's presence (17) may have helped because Spassky now won Games 13 and 14. When Portisch offered a draw at 5:55 pm in Game 15, the match was lost for him. (18, 19)
Geneva, Switzerland, 3 July - 19 August 1977
Elo 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
Spassky 2610 ½ ½ 0 ½ 1 ½ ½ 0 1 ½ ½ ½ 1 1 ½ 8½
Portisch 2625 ½ ½ 1 ½ 0 ½ ½ 1 0 ½ ½ ½ 0 0 ½ 6½
Spassky advanced to the Korchnoi - Spassky Candidates Final (1977/78). His victory also qualified him for the Portisch - Spassky Candidates Quarterfinal (1980).
Notes
1) Harry Golombek in The Times, 18 June 1977, p. 12.
2) Journal de Genève, 1 July 1977, p. 11.
3) Journal de Genève, 5 August 1977, p. 8.
4) De Telegraaf, 10 August 1977, p. 17.
5) Journal de Genève, 23 August 1977, p. 14.
6) Golombek in The Times, 23 July 1977, p. 10.
7) De Telegraaf, 13 July 1977, p. 17.
8) Leeuwarder courant, 25 July 1977, p. 19.
9) The Times, 27 July 1977, p. 7.
10) For a week's rest according to Golombek in British Chess Magazine, Oct. 1977, pp. 459-460.
11) Amigoe, 1 August 1977, p. 6.
12) De Telegraaf, 5 August 1977, p. 19.
13) Journal de Genève, 10 August 1977, p. 9.
14) Amigoe, 8 August 1977, p. 6.
15) De Telegraaf, 10 August 1977, p. 17.
16) The Times, 15 August 1977, p. 4.
17) De Telegraaf, 8 August 1977, p. 15: Smyslov was a reporter for the chess magazine 64.
18) The Times, 17 August 1977, p. 5.
19) Journal de Genève, 20 August 1977, p. 17.
Original collections: Game Collection: WCC Index (Spassky-Portisch 1977) by User: nescio and Game Collection: Spassky - Portisch Candidates Semifinal 1977 by User: Tabanus. Thanks to User: WCC Editing Project and User: Paint My Dragon for help with the language and suggestion of sources.