In the 1966 season he achieved a few superb performances under helpful conditions, such as eight for 18 in the first innings and twelve for 49 in the match against Warwickshire at Coventry but overall the performance was disappointing in this and the 1967 season. In 1967 Jackson took eleven for 69 against Warwickshire at Edgbaston but was dropped from the Derbyshire eleven late in the season.
In both seasons, he showed notable performances under favorable conditions, like eight wickets and twelve wickets, but his overall results were poor. In 1967, Jackson took eleven wickets for sixty-nine against Warwickshire at Edgbaston but was removed from the Derbyshire team late in the season.