For this Ashes series to be considered a success for England, they have got to win it.
With it being five days, I don't see a draw happening in this Test match.
It is worth four points and if England go behind, it will be a huge fight for them to get back in the series.
But results are not the only thing. Success will also be in how Jon Lewis' brand of cricket comes off.
There wasn't much time to judge his impact in the T20 World Cup in February, where England lost to South Africa in the semi-finals and did not get to face Australia.
But generally, since he took over eight months ago, we always felt like the Ashes in England's back yard was a huge opportunity to show they have caught up with Australia.
The manner in which England play this series is important, that they don't shy away from Australia, and that they attack - and we have seen signs of that on day one.
It is going to be a chance for England to show they are making progress with that style of play, and we're also going to get a glimpse of what the future looks like, especially in the seam department.
For so long we had Anya Shrubsole and Katherine Sciver-Brunt and the question was - can England replace them? But on the opening day we've seen that in Lauren Filer, and with Danielle Gibson in the squad, they can.
It is always important to look to win the series, but to do it in a way and a brand that shows us the new era of English cricket.
'It's ingrained in Australia to win - England have to disrupt'
At this early stage, it is hard to tell if the gap between England and Australia is getting smaller because the latter are still 50-over World Cup champions, T20 world champions and Commonwealth Games champions - and they've got the Ashes.
They have dominated for so long. Looking back at the T20 World Cup, we thought England had a chance to beat them but they ended up making some mistakes and losing to South Africa after going back into their shell a bit.
They are certainly the top two teams in the world, but Australia have had the record of dominance and this series is going to be a defining one in telling us whether that gap has got smaller, or if they have stretched even further ahead.
But for the last few years, the difference between Australia and England is not the players.
You can still look at England's line-up and see world-class players in Heather Knight, Nat Sciver-Brunt and Sophie Ecclestone.
But what England don't do is win the key moments, and that's a pressure thing, learning to handle it.
It is about getting on the front foot and staying there, and when you get to the crunch moments they have got to mentally find a way of staying ahead and not backing down.
They need to impose themselves on the scenario rather than just play it out.
If England can force Australia to think differently, make them feel on the back foot for once, that's how they get ahead.
Technically, there is not a huge amount of difference.
It's not about the skill level, it's about the belief. Australia have got such a long history of winning that it's just ingrained in them now, it's ingrained in their mindset and it's ingrained in the younger players that come in and so England have to disrupt that.
They have to attack with their plans and with their approach, and especially with the bat - I think that's why we've seen Danni Wyatt called into the side because she is someone in the middle order who can come in and just throw the game back at Australia.
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'Moments of brilliance and moments of frustration'
It was really interesting at the toss when I spoke to both captains about the conditions because they both read it completely differently.
Alyssa Healy said it's green on the surface but dry underneath, so she wanted to bat first and bowl two spinners, but Knight said it was green on top but thought it would seam and swing, so she would have bowled first.
But it didn't do that, and England bowled first anyway so it didn't matter, but they just read things so differently.
England are potentially on the back foot already just because of the tactics on this wicket.
There is one thing that Australia just do not do and that is collapse. We don't see them lose wickets in clusters.
So they have lost a few wickets, probably one more than they would have liked, but the run-rate has been good throughout and every batter that has come in and kept that going.
For England, there have been moments of brilliance but moments of frustration.
The brilliance for me was Filer, her impact, nearly having Ellyse Perry out first ball.
Ecclestone kept things tight all day and took three huge wickets to give England and Knight some much-needed control.
But around that there have been dropped catches, and moments where England potentially could have been tighter and let Australia get away.
But it's been Australia's day and the way they are shaping up, it feels like they are going to set the tone with a strong first innings.
Ebony Rainford-Brent was speaking to BBC Sport's Ffion Wynne.
