First-Class Batting and Fielding in Each Season by Iain O'Brien
| Season | | Matches | Inns | Not Out | Runs | HS | Ave | 100 | 50 | Ct | St |
| 2000-01 | (New Zealand) | 10 | 9 | 1 | 35 | 18 | 4.37 | 0 | 0 | 0 | |
| 2001-02 | (New Zealand) | 2 | 3 | 2 | 15 | 11* | 15.00 | 0 | 0 | 1 | |
| 2002-03 | (New Zealand) | 8 | 10 | 4 | 49 | 14* | 8.16 | 0 | 0 | 1 | |
| 2003-04 | (New Zealand) | 6 | 5 | 2 | 37 | 18* | 12.33 | 0 | 0 | 0 | |
| 2004-05 | (New Zealand) | 7 | 9 | 2 | 53 | 28 | 7.57 | 0 | 0 | 3 | |
| 2005-06 | (New Zealand) | 3 | 4 | 2 | 23 | 9* | 11.50 | 0 | 0 | 2 | |
| 2005-06 | (Sri Lanka) | 2 | 1 | 0 | 0 | 0 | 0.00 | 0 | 0 | 1 | |
| 2006-07 | (New Zealand) | 7 | 7 | 2 | 81 | 44 | 16.20 | 0 | 0 | 0 | |
| 2007-08 | (New Zealand) | 6 | 7 | 2 | 30 | 10 | 6.00 | 0 | 0 | 0 | |
| 2007-08 | (South Africa) | 3 | 6 | 1 | 20 | 14* | 4.00 | 0 | 0 | 0 | |
| 2008 | (England) | 5 | 7 | 1 | 58 | 31* | 9.66 | 0 | 0 | 0 | |
| 2008-09 | (Bangladesh) | 2 | 1 | 0 | 5 | 5 | 5.00 | 0 | 0 | 0 | |
| 2008-09 | (India) | 1 | 1 | 0 | 0 | 0 | 0.00 | 0 | 0 | 1 | |
| 2008-09 | (New Zealand) | 5 | 7 | 3 | 65 | 19* | 16.25 | 0 | 0 | 2 | |
| 2008-09 | (Australia) | 3 | 6 | 0 | 20 | 14 | 3.33 | 0 | 0 | 0 | |
| 2009 | (Sri Lanka) | 3 | 5 | 1 | 48 | 18* | 12.00 | 0 | 0 | 3 | |
| 2009 | (England) | 7 | 9 | 1 | 110 | 31 | 13.75 | 0 | 0 | 1 | |
| 2009-10 | (New Zealand) | 4 | 7 | 1 | 68 | 31 | 11.33 | 0 | 0 | 1 | |
| 2010 | (England) | 7 | 9 | 1 | 39 | 14* | 4.87 | 0 | 0 | 1 | |