On Monday, it was reported that Doyle is being replaced as Channel Seven's weekend newsreader by Michael Usher – who defected from Nine's 60 Minutes last week.

If anything, it's a weight off her shoulders.

At first glance, this might seem like an odd decision by Seven. The network's news bulletin is winning the ratings this year, averaging 1.03 million metropolitan viewers to Nine's 993,000.

But news has always been a state-by-state battle. In Adelaide, Seven is streets ahead. In Perth, Seven's Rick Ardon and Susannah Carr are more than double their Nine rivals, and have been been No.1 since the dawn of time. But on the east coast, Seven is losing.

So far this year, Doyle has averaged 216,000 Sydney viewers across her Friday and Saturday bulletins – compared to the 248,000 watching Georgie Gardner on Nine.

Before you blame Doyle for not winning, remember: many of her colleagues are also in second place. Seven's Sunday-to-Thursday Sydney newsreader Mark Ferguson is averaging 268,000, behind Nine's Peter Overton on 314,000. Seven is No.2 in Melbourne as well. Even Sunrise is losing to Today.

Newsreaders are often held unduly accountable for a bulletin because they're its most public feature. But dwindling ratings can reflect other problems: annoying graphics, a general dumbing-down, a maddening tendency to repeat top stories every 10 minutes. Perhaps viewers aren't actually angry; they just prefer the competition. Trying to "fix" everything, therefore, might alienate the ones who've stuck with you.

Several years ago, Melbourne newsreader Peter Hitchener lost his crown to a resurgent Seven. Had Nine axed their popular host, it's doubtful they'd be enjoying the big lead he's since re-claimed: 358,000 over Peter Mitchell's 318,000.

For this reason, Usher is not a magic bullet for Seven, but part of the puzzle. News chief Craig McPherson knows it will take time – and a decent editorial strategy – to chip away at Nine's east coast dominance.

So why did Seven attend to its weekend news bulletin only, in the middle of the year?

In commercial television, you grab opportunities as they arise. Usher has long harboured newsreading ambitions, and 60 Minutes' reputation has been battered by the Beirut kidnapping saga. He was ripe for the poaching.

Giving Doyle an expanded role on Sunday Night makes better use of her talents. She's a good newsreader – but viewers prefer her in less constricted roles. And those who think she's a soft-touch interviewer have never seen her grill a politician on Sunrise.

Doyle, who also hosts weekend mornings on Smooth FM, is one of the great survivors of broadcast media. She's rumoured to be very happy with her new arrangement – and why wouldn't she be? It's the kind of job most commercial TV journos crave.

And commercial TV news has never been tougher. Social media and news websites are eroding younger audiences. Prime-time bulletins must be tailored to each city. They're expensive and require lots of staff. So why do they persist?

News viewers are remarkably loyal, if you get the bulletins right. The prize: a hefty core audience, not just for an eight-week season, but all year around. The stories can be used throughout the day, from breakfast TV to late-night updates. The prime time services are a good platform to promote other shows – and provide a big "lead in" audience to evening reality and drama. Sometimes, they are the top-rating programs.

All of which makes networks eager to be No.1 – any way they can.

In July, Nine bestowed victory upon its Sydney and Melbourne services after winning more than half the 40 official ratings weeks this year. Seven was suitably outraged, declaring this "a bit like a half-time victory lap".

And as Seven keenly points out, its news audiences in Sydney, Melbourne, Adelaide and Perth have grown since last year. Nine has gone backwards in the five major cities.

"When the race gets close," an experienced TV reporter told me last year, "it goes either way. You hunker down and stay the course. Or you blow things up – fire a presenter, change the set, extend your show even – to gain an edge."

Twitter: @Michael_Lallo