O'Brien made his debut for the national side in March 2005 following injuries to senior international players, such as Shane Bond, Daryl Tuffey and Chris Martin but has been in and out of the side since to replace injured and retired players. He made his One Day International debut against the England cricket team, and had a tough debut, with figures of 1/59 in 6 overs. However, between 2007 and 2009 he established himself in the Test side, and to a lesser extent, in the ODI side, particularly in the absence of Shane Bond and he is renowned as an 'into-the-wind' bowler who would often bowl at an end that did not offer favourable bowling conditions—especially at Wellington, a ground renowned for strong winds. He enjoyed much success as a fast bowler for the Black Caps, with great performances against England in the UK, and against the West Indies cricket team at home, where he took his best Test figures of 6/75, in a spell of bowling regarded as one of the best in New Zealand. These performance have given him the reputation as a wicket-taking bowler, and being the go-to man for Daniel Vettori, the captain. He continued his consistent spells against the Australia cricket team, home and away, and for Wellington. During New Zealand's tour of England in 2008, he had had similar success, taking 15 wickets at 26.80. Against the Pakistan cricket team at home in December 2009, he has become well known for bowling New Zealand to victory by taking 3 wickets while suffering from a broken thumb. In this same series, he took 6 wickets in the next game, including 4/66, dismissing the likes of Salman Butt, Imran Farhat and Misbah-ul-Haq. In December 2009, he announced his decision to retire from international cricket to spend more time with his wife in England and this decision prompted Middlesex to sign O'Brien as their overseas player for the 2010 season.
Domestic career
He played at Leicestershire during the 2009 season as their overseas player, impressing by taking 21 first-class wickets at an average of 26.04 in a struggling team, including 9 wickets in a game where he took 6/39 on his birthday. The 2010 season was a frustrating one for O'Brien, he took 23 wickets at an average of 27.30 for Middlesex in division two of the County championship. However, injury restricted his appearances for Middlesex to just seven championship matches, one CB40 match & a single FP Twenty20 match.
Writing
Part of O'Brien's appeal to fans is because of his writing, both for his own blog and for cricinfo. Rarely has an international cricketer been so candid about his own faults during his career. O'Brien's blog is not updated straight away after all games, but he generally talks about all games he has played in. It is a far cry from the ghost written columns of most cricketers, and has got him in hot water with NZC before. O'Brien really enjoys writing and has already been a special guest writer in the book Ashes 09: When Freddie Became Jesus and is contributing to a book on New Zealand Indoor Cricket as well. O'Brien also is an occasional contributor to Test Match Sofa – an online alternative cricket commentary service as well as BBC and Sky cricket commentary teams.
