The Irish No 2 won his first title by beating Anthony Hamilton 9-7 in a classic final last April, but snooker's governing body decided to bring the event forward this season to ease congestion on the calendar, so the next edition of the tournament starts today at the Plymouth Pavilions.
O'Brien starts his defence at No 11 in the rankings but the 27-year-old from Dublin said: "The hard work doesn't stop just because I've won a tournament and got into the top 16. Now is just the start. That's why I have been practising hard over the summer as well as taking a few holidays."
The bonus for winning the British Open was an invitation to last week's Champions Cup in Croydon, where O'Brien narrowly failed to make the semi- finals, but he believes the match practice will be invaluable in Plymouth.
"Twelve months ago I went there for three qualifying games and lost the lot. Now the top players are warmed up and no longer at a disadvantage," he said.
O'Brien is one of 128 players chasing an improved first prize of pounds 62,000 from a total fund of pounds 400,000.Reuse content