Currently, in a random split branch in workflow, HubSpot enforces an equal distribution. It’s not possible to adjust the percentage:
It would be great if it was possible to adjust these percentages, the same way that list splits are allowing for custom / flexible splits:
Thank you for considering this request!
This is much needed, when we run AB tests we want to also be able to rank against a 10% control group.
This will solve a lot of pain in lot of places! also, if hubspot can allow by teams that would great an extra added feature!
I assumed we could adjust the percentages as I’ve used this w/ an equal split w/ a few workflows. Then I had one where I wanted to adjust the percentages manually and learned this wasn’t possible. While not perfect and it lacks some granularity, I created a random distribution branch in my workflow with 10 branches. Branches 1, 2, 3 and 4 held the main work flow. I directed branch 5,6 to branch 1 thus giving this a 30% chance of hitting branch 1. Branch 7,8 pointed to 2. And 9, 10 pointed to 3 which gave me the distribution i was looking for: 30%, 30%, 30% and 10%. Ideal? No, but it works.
Nice workaround @TeddyRuxpin
This is necessary
This seems necessary and logical seeing as you can already use preset, equal percentage splits.
This would be extremely useful.
100%!!! Generally A/B testing is done with a small portion of customers (ie 10%) to start off with. To get that type of split, we have to separate each email into x10 versions to get that type of split. And that’s for one email in a workflow. What if we have 2+ emails in a workflow??.. the number of branches exponentially grows and becomes unusable!
PLEASE can we get customisable random distribution options! Pleeeeease!!! (and thank you).
I fully support this idea! 
In our lead assignment process, we need flexible weighted splits to ensure a fair assignment of new leads. Currently, we’re forced to use custom code for a weighted lead rotation – which works, but adds unnecessary complexity and makes maintenance harder.
A native feature for weighted random splits (including custom percentages) would make these workflows far more reliable, scalable, and accessible for teams who manage lead assignment.
