Field is an awful poll, yet year after year the press continue to quote them, yet their early polls very seldom have any correlation to the outcome. As for "likely voters" those are self-screened likely voters, so it doesn't hold much weight.
If you want to dig further find out about their sampling. What percentage of the calls went to San Francisco County? vs. Placer County. Field sample based on the populations of counties, rather than the percentage of people statewide who are likely to vote from that county.
Who's getting your vote for Gov, Dan?