Strategic Mayoral Voting / Do we trust the polls?

I have been planning to vote for Andreas Addison for mayor. HOWEVER. I really don't want to see Michelle Mosby as mayor -- for myriad reasons already well covered by others in this sub.

The only polling I've seen so far is from Avula's campaign (so taken with a hefty grain of salt) and it shows that he and Mosby are the two most viable candidates. If I had to choose between the two, I would vote Avula.

Can someone who is good at math and understands Richmond city's electoral system help me understand whether voting for Addison would help Mosby's chances? Can I vote Addison in the first round and then Avula in a run off if there is one? I'm in the 7th district, if that helps.

I'm sure there's plenty I'm not thinking about here, but I got spooked by the polls and want my vote to work for me. TIA!