List A Bowling in Each Season by Iain O'Brien
| Season | | Balls | Mdns | Runs | Wkts | BB | Ave | 4wI | 5wI | SRate | Econ |
| 2003-04 | (New Zealand) | 108 | 1 | 79 | 2 | 1-34 | 39.50 | 0 | 0 | 54.00 | 4.38 |
| 2004-05 | (New Zealand) | 186 | 0 | 155 | 7 | 5-35 | 22.14 | 0 | 1 | 26.57 | 5.00 |
| 2005-06 | (New Zealand) | 204 | 4 | 128 | 9 | 5-43 | 14.22 | 0 | 1 | 22.66 | 3.76 |
| 2005-06 | (Sri Lanka) | 209 | 0 | 197 | 2 | 1-39 | 98.50 | 0 | 0 | 104.50 | 5.65 |
| 2006-07 | (New Zealand) | 492 | 9 | 382 | 10 | 3-39 | 38.20 | 0 | 0 | 49.20 | 4.65 |
| 2007-08 | (New Zealand) | 312 | 4 | 265 | 9 | 4-44 | 29.44 | 1 | 0 | 34.66 | 5.09 |
| 2008-09 | (New Zealand) | 639 | 2 | 544 | 13 | 3-43 | 41.84 | 0 | 0 | 49.15 | 5.10 |
| 2008-09 | (Australia) | 270 | 2 | 253 | 10 | 3-68 | 25.30 | 0 | 0 | 27.00 | 5.62 |
| 2009 | (England) | 298 | 3 | 243 | 7 | 2-32 | 34.71 | 0 | 0 | 42.57 | 4.89 |
| 2009-10 | (New Zealand) | 60 | 2 | 45 | 2 | 2-45 | 22.50 | 0 | 0 | 30.00 | 4.50 |
| 2010 | (England) | 40 | 1 | 41 | 4 | 4-41 | 10.25 | 1 | 0 | 10.00 | 6.15 |