Adobe Target gives us the ability to auto-allocate traffic in testing. To reach the statistical significance for a winner to be determined, the conversion rate asks us to ensure each offer/experience receives 1000 visits and 50 conversions per day for accurate confidence intervals.
For web pages that receive less traffic, can we set/change the threshold for determining a winner?
There isn't currently a way to change the threshold for the winner badge in Target. It sounds like a good feature request you should consider submitting.
I think the theory behind the badge is to help clients understand there is a potential winner. It will always require verification from someone that can check consistency and validity of the data. Perhaps we should relabel the badge "potential winner".