It’s an historic field of candidates. And five of them are battling for the voters' attention. They may be swimming in the same pool, but they are trying to find the lane that will bring them to victory and the mayor's office. You'll hear a lot of aquatic metaphors in this installment of The Scrum. So, brace yourselves. Our political analysts, Professor Erin O’Brien from UMass Boston and Lisa Kashinsky of POLITICO Massachusetts Playbook, get into it with hosts Adam Reilly and Saraya Wintersmith. “If you ask the candidates, of course they’re going to say they’re very different,” O’Brien said. “Most voters aren’t policy nerds like us, and so it’s more personality. And that’s why people are having a hard time choosing.” GBH politics editor Peter Kadzis offers some context on recent developments -- the harbor development plan (scuttled) and the eviction moratorium (launched) -- with which you may or may not agree, but which will grab your attention. As with last week’s episode, you can watch the discussion on video, here.