Ahead of each round of fixtures in the Premier League, W2W4 looks at the main storylines to keep an eye on.
1. Liverpool can prove just how much they've improved
It's always difficult to get a handle on the truth when teams win games while not playing especially well. Do we assume that those results were semi-flukes and that a crash is coming? Or is it a sign that if they can collect maximum points without reaching their own maximum, then the rest of the league had better watch out? It's not that Liverpool have been bad in their four fixtures so far, simply that there's been a strong sense there is plenty more to come from them.
The trip to Tottenham at the weekend obviously represents their toughest test of the season so far, but it's also a useful barometer for how much the Reds have improved on last term's biggest weakness: away games at their immediate rivals. It's just over a year since they were battered 5-0 at Manchester City, and around 11 months from the day Spurs took them apart at Wembley. Last season Liverpool lost five league games, and four of them were against rivals (add the 2-1 loss at Manchester United and the 1-0 defeat to Chelsea at Stamford Bridge to the list).
In theory, everything is there. Liverpool now have arguably the best defence in the Premier League (assuming Alisson's aberration against Leicester last time out was merely that) and a midfield improved by Naby Keita and eventually Fabinho, while that whirling, twirling, goalscoring forward line is still in place. Saturday is the time to turn theory into reality, and prove that those first four games have merely been them warming up.
2. What's eating Harry Kane? Is anything eating Harry Kane?
It's been a weird six months or so for Harry Kane. Over most of that spell, Kane has looked sluggish, often off the pace, seemingly a man either playing through an injury or an extended period of bad form. But in that time, he's won the Golden Boot at the World Cup, bagged two in Tottenham's first four matches, dismissed the admittedly slightly silly notion of an "August curse" with a goal against Fulham and scored at Old Trafford.
But he undoubtedly doesn't look himself. The problem isn't fatigue, according to Mauricio Pochettino anyway. "We know Harry Kane well and have worked with him the last more than four years, and we know this is not a situation that worries us," he said on Thursday. So who knows what the problem really is. Who knows if there is actually a problem. What we do know is that if he excels against that brilliant Liverpool back five on Saturday, the problem can't be that big.
3. Would Watford beating United even be an upset?
It's easy to forget that Watford were heading for relegation when Javi Gracia arrived in January. Now, having avoided the drop comfortably, they go into Saturday's game against Manchester United with a perfect record from four games, and among the finest compliments that could be paid to Watford and Gracia is that it probably wouldn't register as an upset if they won.
Last weekend's win at Burnley will convince precisely nobody that things are fine and dandy at United, Jose Mourinho's side still looking barely anything like a side that could challenge for the league title. Throw their defeat at Vicarage Road last season in alongside Watford's fine form, and you've got the strong potential for this to be an implausible fifth win from five for Gracia's men.
4. Will Burnley's slow start become a crisis?
This week Joe Hart insisted there is more to come from Burnley. There had better be, really -- otherwise this is going to be a very long season ahead for Sean Dyche's men, who have gained just a single point from their four games so far. Last season, a game against a newly promoted side might have looked appetising for the more established Clarets, but only one of them and this weekend's opponents Wolves have looked like they belong in the top flight so far this season.
The distraction of the Europa League was the reason that many thought Burnley might struggle, but with that out of the picture and a week or so to breathe during the international break, Dyche's side now have no excuses. Should they lose to Wolves, everyone will wake up to the potential season of struggle at Turf Moor.
5. The latest step towards VAR is taken
The most interesting part of this weekend might not happen on the pitch, but rather in a windowless room somewhere in west London. For the first time in the Premier League, video assistant referees will be trialled in five games on Saturday to fully test whether the system can be made to work in concurrent games, as opposed the single cup matches for which it has been used in England so far.
This is most certainly a dry run, because there will be no contact between the men watching the Premier League's bank of VAR monitors and anyone at any of the grounds. Indeed, one wonders just how much use the trial will be, given that one of VAR's key components is how it meshes with the officials at the games. But this feels like a box-ticking exercise, necessary admin on the path towards VAR being implemented in all 380 Premier League games over a season. VAR is coming, whether we like it or not.