Morteza Mahjoob breaks Guinness Simultaneous Chess World Record
The Guinness World Record for the largest number of simultaneous games played 
  in a single session was initially set in 1996 Swedish Grandmaster Ulf Anderson, 
  who took on 310 opponents. This record was broken in 2004 by British IM Andrew 
  Martin, author of many of our openings 
  training DVDs. Martin played against 321 opponents, scoring 294 wins, 26 
  draws and 1 loss for a winning percentage of 95.64%. In August 2005 GM Susan 
  Polgar played 
  against 350 players simultaneously at the Gardens Mall in Palm Beach Gardens, 
  Florida. Finally, in February this year, Bulgarian GM Kiril Georgiev played 
  a simultaneous 
  exhibition against 360 opponents. 

  The latest record attempt by Iranian GM Morteza Mahjoob
Recently Iranian GM Morteza Mahjoob, 29, took it on himself to break this record 
  – actually smash it to little pieces. He planned a simultaneous exhibition 
  against 500 players, which entailed walking for about 40 kilometers and staying 
  awake and sharp for up to 24 hours.

  The training phase: Morteza Mahjoob preparing for his physical ordeal

  The GM had to be ready to walk 40 kilometers and stay awake and fit for 24 hours
The name of the world record attempt was Rokh-dar-rokh 500 (rook vs 
  rook 500). The opening ceremony began on August 13th at 9:00 a.m., with nearly 
  700 participants (500 players and 200 reserve players) present. In addition 
  there were nearly a thousand spectators at the playing venue "Yadegar-e-Emam", 
  a multi-purpose sport saloon in the "Engelab Sport Complex" in Tehran.

  A crowd has collected at 9:00 a.m. in front of the Engelab Sport Complex 
  in Tehran

  Dignitaries: Kiomars Hashemi, Vice President of the Iranian National Sports 
  Organization; FIDE Vice President Nizar Elhaj (middle), President of 
  the Iranian Chess Federation Dr. Mohammad Ebarahim Maddahi (right)

  The President of the Iranian Chess Federation Dr. Mohammad Ebarahim Maddahi

  Iranian soccer star and manager Peyrovani is interviewed at the site

  Iranian Taekwondo champion Behzad Khodadad (watch him in action here)
The President of the Iranian National Olympic committee, Mohammad Ali Abadi, 
  who is also the Iranian vice President, some of his deputies were also at the 
  location: FIDE Vice President Nizar Elhaj, who came as the official observer 
  for FIDE, the President of the Iranian Chess Federation Dr. Mohammad Ebarahim 
  Maddahi and many well-known Iranian sportsmen such as Hadi Saei, three times 
  Olympic medal winner and recent Olympic Champion in Taekwondo, who is a member 
  of the Tehran Council. Finally a number of famous actors and movie stars participated 
  in the ceremony.

  Preparing the venue for the mammoth event

  Everything is in place, the simultaneous master and his opponents can start 
  playing

  Iranian TV talks to GM Morteza Mahjoob before the start of his record attempt

  The GM and Hadi Saei, Olympic medalist in Taekwondo, are interviewed
The games officially started at 10:00 o'clock. The 500 players all were present 
  at the time on their boards. GM Morteza Mahjoob executed his first five moves 
  in two hours. The first (and only) break, for lunch, was after the ninth move 
  at 14:30 to 15:00. After the break all players came back to their boards and 
  games continued. 

  GM Morteza Mahjoob starts his simul on board one of five hundred at 10:00 
  a.m.

  An Iranian lady helps her grandson to prepare for his game against the grandmaster

  The master moves from board to board, making his first moves in this exhibition

  1.Nf3 was one of the opening moves the grandmaster used

  The jacket is off for the second round of moves
Just after midnight there were 130 players left. Many of them had no chance 
  of winning, but they insisted on 
  playing on. There were some kids and semi-professional teenage players who resisted 
  for more than 15 hours. 
  Their parents helped them by massaging them. Some of the players who hung on 
  for 15 hours needed medical attention. One of Morteza Mahjoob's chess students, 
  who is six years old, won his game against his teacher. This kid was amongst 
  the last ten players in the simul. 

  A very youthful opponent, a student of the Master, won his game in the simul
At 23:30 Morteza had succeeded in achieving 88.42% over 364 boards. The remaining 
  games continued and finally at 04:12 on August 14, 2009 he finished the last 
  game.
The final result over 500 boards was: 397 wins, 90 draws, 13 loses, with total 
  score of 442/500 points and score percentage of 88.4%.

  The long cycle time between moves was not just tiring for the master

  Even the older players felt the strain
  
    Women's chess is definitely on the rise in Iran
 
The main sponsor of this event was Candy, 
  an Italian producer of home appliances. The sponsor covered all organizing expenses 
  as well as cash prizes for every winner and everybody who could make draw. There 
  were also some prizes from their products, drawn by lottery, for spectators.
The organizer of the event was the Iran Chess Federation. Chief organizer and 
  technical director was IO Hadi Karimi, Chief Arbiter was IA Hosseingholi Saloor, 
  first deputy of chief arbiter was IA Hamid Reza Pourshahmari. Three other Deputy 
  Arbiters were: IA N. Kananazar, IA F. Eskandary, IA. H. Kazemiashtiyani. Two 
  FIDE Aribiters and 48 National Arbiters refereed in this event. Near 30 people 
  helped in the organizing team.

  The arbiters and organisers pose for a group photot
The oldest and youngest players were 81 and 4 years old. Many international 
  and national rated players participated and showed stiff competition. Also three 
  strong blind Iranian chess players competed all the way until the final hours.

  A blind Iranian chess player amongst Mahjoob's simultaneous opponents
Many TV channels and other Media covered the event from beginning to end. The 
  games had live coverage by IRIB3 (Iranian National broadcasting) for near two 
  hours in three different segments. All daily newspapers as well as all news 
  agencies put the event on the front page.

  Flowers for the record-breaking GM from football manager Farhad Kazemi
 
   
    The simultaneous master at the end of his 18-hour ordeal
 
All photos provided by Mehdi Mahjoob
  
Videos of the record simul (in Farsi)
 
  
  Part one
 
  
  Part two
 
  
  Part three
Links