"teams which" or "teams who" [duplicate]

It should be noted that simply looking at the frequency of the pronoun doesn't tell you a lot. One also needs to consider the context. In particular, "who" is more likely to "fit" when the reference is to the individual team members, rather than the team as a whole.

Also, many of the hits for "which" in "corpus" scans in another answer are in sentences such as "The last 11 losers of Super Bowls are 11 different teams which indicates it's much easier to get here than to actually win." "Which" is being used in an entirely different sense.

Neither who nor which are as common as that, which is what should be used. Note that that that solves one problem and avoids others. It works for singular and plural, masculine, feminine, and neuter, and works for any relative clause with a subject relative pronoun.

• the man that came to dinner
• the book that's on the table
• the teams that won the first round

It also works for non-subject relative pronouns, but that's irrelevant here. So, your understanding about which relative pronouns to use seems incomplete. Who and which may indeed be used -- either one, in the case of teams -- but that is preferable because it's colloquial English.