ATP promises to fix the problems from last year's Finals in London

Considering that more than 100,000 tickets had been sold within 12 hours of the box office opening yesterday it might have been a safe assumption that organisers of the Barclays ATP World Tour Finals would merely try to repeat last year's formula.

However, a number of changes will be made when the men's end-of-season showpiece returns to London's O2 Arena from 21 to 28 November. The event will still feature the year's eight most successful singles players and doubles teams, but lessons have been learned from 2009.

There will again be afternoon and evening sessions – both featuring a doubles match followed by a singles match – but, to the relief of spectators dependent on public transport home, start times have been moved forward 45 minutes. The afternoon sessions will start at 12.15pm and the evening at 6.15pm.

Most importantly, the final singles match of the day will start at 8pm. On the concluding Sunday the singles final will not begin until 6pm in order to give the winner of Saturday evening's semi-final sufficient time to recover.

There should also be no repeat of the farcical scenes last year, when confusion reigned at the end of the final match in one of the four-man round-robin groups. Juan Martin del Potro and the crowd were kept waiting several minutes before it was announced that the Argentinian, thanks to his victory over Roger Federer, had qualified for the semi-finals at the expense of Andy Murray.

The delay, which meant that most spectators left without knowing the outcome, occurred because the successful qualifiers had to be confirmed off-court by the ATP supervisor, who also had to be on court during play. This year an extra official will take charge of the qualifying system, while the crowd will be regularly updated on who needs to do what to go through.

Among other changes, more space is being made available to build a "fan zone", which will include two practice courts with seating for 400 spectators. Last year's event, which was won by Nikolay Davydenko, was watched by a cumulative crowd of more than 265,000 in the 17,500-capacity arena, a record for an indoor tennis tournament. The cheapest tickets again cost just £20, with under-16s half price.

Chris Kermode, the event's managing director, hopes the tournament will be a sell-out from the first session to the last. "Because of the round-robin format it's a strong event right from the first Sunday," he told yesterday's launch in London. "There's a perception that some tournaments are weaker at the start, but that isn't true here. The top guys are playing each other right from the start."