Here are all the details47 on how ConvertKit does A/B testing, but let me give you the highlights:
- ConvertKit will send option A to 15% of the list, and option to 15% of the list. Note that 7 is about 15% of 41 (with some rounding occurring).
- Four hours later, ConvertKit will send the message to the other 70% of your list using whichever subject line "won" in the testing. This is the other 27 folks in your example.
- Lastly, with the numbers you're sharing, a split test is not going to be statistically significant. In general you'll need a list of over 1,000 folks to have it show meaningful differences.