In the first and second seat, we have to be sound when opening as our partner hasn’t bid yet. In the third seat, we strain to open in order to get up fourth seat’s nose.
In the first and second seat, we use the Rule of 20 to decide whether or not to open one of a suit. In the third seat, we drop this to Rule of 19.
Similarly, where we would pass a 4-4-4-1 12-count in the first two seats, we would quite happily open it in the third seat.
Preamps in the third seat can be imaginative as partner has limited_ their hand by passing. remptingg on a good six card suit is acceptable.As is pre-empting with as much as a 12-count.