There have been moments at the Fiera Milano this week that felt like one of those dreams where nothing is quite as it should be.
Where are the tramlines? Why are fans wandering around between points? What’s happened to the line judges?
Then you catch yourself and remember this is the Next Gen ATP Finals, which brings together the best under-22 players from 2018 and is experimenting with all the possible rule changes - and plenty more besides - that have been talked about in tennis circles for years.
There are so many innovations going on simultaneously that it was hard to disagree with Andrey Rublev when he said "everything make no sense."
But this was not meant as a criticism, nor should it be read as one. The best way to experience the Next Gen Finals, which enters the semi-final stage on Friday, is to embrace the chaos. Not all the rules being road tested will ever catch on, but that doesn't mean they're not worth trying.
As ATP president Chris Kermode, whose brainchild the event is, told The Telegraph on Monday “We need everyone’s input and maybe we make some tweaks to the sport, maybe we go radical, or maybe we leave it exactly as it is.”
Take for instance the introduction of a towel rack to stop players treating ball-kids as their personal slaves - an issue brought to the fore by Fernando Verdasco barking at an unfortunate youngster in September.
Greece’s world No. 15 Stefanos Tsitsipas - the most high-profile player in Milan - surprised reporters by going against the grain of public opinion and saying on Tuesday that he did not like having to fetch his own towels.
“One thing I didn’t like that much was the towel thing,” Tsitsipas said. “I always had to run for the towel, always had it in my mind ... I think the ball kid, it’s their job to provide towels and balls for the players.”
Frances Tiafoe admitted the towel rack was the "only rule I don't like", while Rublev disagreed and said he "was okay" with it.
Other new innovations for this year include a VAR-like system where players can appeal contentious calls like double-bounces, net touches, or shots played before the ball has crossed the net. This has not been required thus far but adds an extra element of intrigue. Another reform sees the warm-up shortened further from last year's five minutes to four minutes.
— Next Gen ATP Finals (@nextgenfinals) November 8, 2018
As with the 2017 inaugural event, matches are played with no line judges (Hawk-Eye takes care of all out calls), no service lets, and a radically revised scoring system that includes sudden-death deuce points and best of five sets to four games.
The Hawk-Eye line calls have been almost universally applauded by the players - even if as spectators it takes a while to get used to automated voices screaming "out".
The quickfire scoring system meanwhile goes right to the heart of tennis, and forces us to ask fundamental questions around what kind of sport we want it to be.
According to Kermode, the quicker format is there to see if tennis can be made more appealing to a younger audience. At present the average tennis watcher is over 60.
"What is a concern is how do we engage twenty-somethings in the sport, and I just feel like we have to look ahead at what the sport could - and I stress could - look like," Kermode said.
The desire to make tennis quicker is a sport-wide issue. After trials at last year's US Open and Next Gen Finals, various tournaments have introduced a shot-clock to speed up the time spent between serves, while even the arch-traditionalists at Wimbledon have announced a final set tie-break at 12-12.
With speed the name of the game in Milan, what then has worked well over the last few days?
The first-to-four-games scoring system is designed to reduce the number of less important games at the start of sets, and it does make for an intense spectacle. Sets can fly by in not much more than 10 minutes, as happened in Taylor Fritz’s win over Liam Caruana, with one service break usually terminal to a player's chances. The sudden-death deuce rule acts as a shot of adrenaline, with some points simultaneously match and break points.
The players are divided over the quick-fire scoring system, which some feel adds an element of randomness.
A frazzled looking Tsitsipas described the rules as "stressful", while Rublev added: "Like I always said I'm not a big fan of these rules. I think it's a little bit not fair. It's not as physical and you don't need to be as strong.
"Look, for example, the match today of Tsitsipas, who has had an amazing season beating top players, and now - I'm not saying nothing bad about [his opponent Jaume] Munar - but Tsitsipas is top 15 and Munar is, I think, 80, 90 in the world [actually No. 76] which normally Tsitsipas would be supposed to win, like, not easy but with confidence, and instead the match was so close."
In a similar fashion, many doubles players resent the "match tie-break" that reduces final sets to a first to 10 point shoot-out.
On the flipside, the American pair Tiafoe and Fritz have enjoyed the format. "I like it a lot," Fritz said after defeating Caruana on Wednesday. "I think it makes tennis more entertaining and it's trying something new. So I think tennis needs to try to appeal to be more exciting and get younger fans involved. And everyone I've talked to said they find this more exciting. They want to be watching the whole match, and I like that.
"The sets to four games, three out of five, I really like that. Because sometimes I can find myself getting bored in, like, a set just holding serves a lot. Like, get me to a tie-breaker. Or if I drop my serve, then I'm upset at the beginning of the set and I have to be upset about it the whole entire set. In this format, if you're playing a bad set, it's over with and you're right into a new one quickly. So I like that a lot."
Of the sudden death deuce points, Tiafoe joked: "Definitely not the no-ad because, I mean, guys like [John] Isner would be No. 1 in the world. There's no way you could beat him."
As a viewer, an additionally intriguing element of the no-ad deuce rule is seeing which side the server chooses on the sudden-death deuce point. Some players like to change it up, while others stick resolutely to one side. What would Roger Federer or Novak Djokovic’s preferred side be, I wonder?
The no-let service rule meanwhile adds another random element to proceedings - twice favouring Fritz when down break point against Rublev on Tuesday - and feels unlikely to catch on.
Away from the scoring system, the Next Gen Finals uses its own variation of on-court coaching - an issue that has been bubbling away since Serena William's meltdown at the US Open.
Rather than have coaches come onto the court like in the WTA Tour, at the Next Gen Finals players communicate with their coaches via a headset at the end of each set.
Again, this has provoked a range of responses and debates. Tsitsipas said he is vehemently against on-court coaching of any kind, while Rublev said because of the public nature of the conversation he and he and his coach only speak in vague platitudes.
Fritz added: "I disagree with coaching. I think tennis is individual and how you analyze the match yourself should have an important impact on the result."
That said, it was amusing to see coach David Nainkin tell Fritz to go for more backhands down the line against Rublev and for his man to take the advice and instantly smack three winners off that side in the next set.
Elsewhere at the Fiera Milano, the whole event is geared towards having fun. All the players have loved how many children are in attendance - "the next Next Gen", as Tsitsipas joked - and how this makes for a raucous atmosphere. There is also a fan area where punters can play table tennis and mini tennis, which all adds to how interactive and inclusive the event is.
During points spectators can wander around and enter whenever they please, making for a welcome alternative to tennis's usual rules of only being able to enter at the end of every second game.
— Next Gen ATP Finals (@nextgenfinals) November 6, 2018
Visually, the arena is striking with its vivid blue lighting, no tramlines on the court, and red backdrop. There is even a Red Bull DJ banging out big hits, continuing the theme of trying to appeal to Millennials.
Naturally the mood and format of the Next Gen Finals is not for everyone, but then again nor is a drawn-out five-set match between two run of the mill players at a grand slam - and this is precisely the point.
Perhaps tennis needs to be thinking more about how different events can stand out. At the moment the only thing differentiating each tournament is the surface, when as the Next Gen Finals has shown there are so many other ways events can stand out. Meaning no disrespect, there’d probably be more buzz about, say, the Sofia Open if it implemented a best of five sets to four games rule.
Changes to the scoring system will take longer to implement, but, as the introduction of the shot clock has shown, there is appetite for reforms that speed up the game.
Tennis is in rude health right now but it would be naive to not try and evolve when the average viewer is of retirement age.
As Kermode says, “The challenge will be how you keep tennis at successful as it is now while adapting it for the next generation but not ruining it.”
This will not be easy, but events like the Next Gen Finals force us to ask what we want tennis to look like in the future. Maybe it’s more of the same, maybe it’s a complete transformation - but it’s a question well worth asking.