Calculated Field Referencing Multi-Select Checkbox Field
I have a multi-select checkbox field (let's call it "Field 1") with three choices: Team A, Team B, Team C.
I'm trying to make a calculated field ("Field 2") that references Field 1, returning a true expression whenever Team A is selected in Field 1 (regardless of whether the other options are also selected).
I've tried various forms of IF, IFIN, IN, etc, but I am only able to return a true expression when only Team A is selected in Field 1. If multiple selections are made in addition to "Team A", I'm getting the false expression.
One example of a calc I've tried (have tried a few and scrapped):
IFIN(Teams Involved,"Team A","Yes","No")
At this point, "why" I was doing this is moot, but I still want to know what's going on and if there's a proper calculation to use for this scenario.

Can anyone help here?