Traditionally byelections are pretty low-turnout events with usually only about 12,000 people voting. In a big field like this one, that means about 3000 votes are probably all it will take to win the mayoralty. Ms Hazlehurst is probably in prime position because she is a popular councillor and is acting mayor already.
Mr Barber has a well-organised campaign and will mobilise to get Maori voters out. Mr Perry was unsuccessful in his bid for a council seat last time, so probably is the outsider, while Mr Nixon is a perennial stander who is unlikely to get enough votes.
Mr Harvey, a new councillor, is a contender as he has many well-connected friends and powerful business acquaintances in the city. He also sits on a number of boards, so will get support from a variety of groups. Whether he gets any backlash from his wife's failed MP bid remains to be seen.
Another interesting battle lies ahead.