How can I do A/B testing on what the most effective saturation control rules are in DESelect Engage?

to validate whether a given saturation control rule is effective, you can apply a/b testing, using the following steps 1\ put your contact base in 3 groups, say a, b and c you could do this by having all contacts go through a journey, where you use a random split in journey builder to assign people to one of the 3 groups, and create a data extension where you store the contact key and the group 2\ set these groups as contact categories in deselect engage note that you can assign multiple contact categories to each contact, so if you already have another contact category set in place, that's not a problem create a new data extension that contains both your existing contact categories data extension and this new one, using a union statement in sql or using the tabs (append) functionality in deselect segment 3\ configure different rules for different contact categories for example for contact category 'a' max 2 emails per week for contact category 'b' max 4 emails per week for contact category 'c' max 6 emails per week make sure to not have other rules that apply to contact categories, as this will impact the results 4\ after some time, eg 30 days, you can look at the engagement metrics of each contact category group if open rates/click through rates etc for one contact category are better, expand the rule defined for that category to apply to all contact categories