Sydney - Five things we learned from the inaugural 24-nation ATP Cup team competition played in Brisbane, Perth and Sydney over 10 days in the lead-up to the Australian Open:
The new tournament won plenty of plaudits, with players also hailing the team spirit and competitive matches.
Fresh innovations were trialled at the ATP Cup, including on-court coaching and team zones in the corners of the court, which were wildly popular.
There was also real-time statistics, data and match vision available to the captain and players, plus a video review system to challenge contentious decisions like foot faults.
While it worked well, there was also high-profile criticism from Novak Djokovic and Rafael Nadal that playing another team event so close to the Davis Cup in November was too much.
"I think is a great competition, but at the same time I can't change my mind that two World Cups in one month is not real. So (it) is not possible," said Nadal after his defeat to Djokovic.
Djokovic underlined his credentials as king of the hardcourts and favourite to win an unprecedented eighth Australian Open title.
The Serbian superstar never looked like losing, coming through tough tests from the likes of Denis Shapovalov, Daniil Medvedev and world number one Nadal in Sunday's final to remain unbeaten over six matches.
"I mean, it is the perfect preparation," said the 16-time Grand Slam winner. "This has been one of the highlights of my career, because you can't really match any big win in tennis with the win that you get to share with your team, with your friends.
"It has been an amazing event," he added.
Big things have been tipped for Alexander Zverev since he burst into the top 10 in 2017, but the 22-year-old is yet to fully deliver. The young German won just one title last year, at Geneva, and slipped down the rankings to seven from four at the start of the season.
He failed spectacularly at the ATP Cup, looking lost on court as he crashed in three-of-three games.
To make matters worse, he was reportedly stung by a bluebottle jellyfish while having swim at an Australian beach, although it was nothing serious.
"It's not really that high," the dejected Zverev said of his confidence. "Generally I'm not playing good, so there's a lot of things that I still need to improve, but it's the start of the season."
Asked how he could fix what was wrong before the Australian Open, he replied: "On the practice court."
Players to watch
Outside of Djokovic, unheralded Spaniard Roberto Bautista Agut and workmanlike Russian Daniil Medvedev emerged as the early-season form players going into the Australian Open.
Bautista Agut, who made the Wimbledon semi-finals last year and edged inside the top 10, went through the ATP Cup unbeaten, winning all six matches in emphatic fashion, dropping just 25 games.
"It's good for me to get confidence at the beginning of the year, to feel well on the court. That means I did a great job this pre-season," said the Spaniard, who made the quarter-finals at Melbourne Park last year.
World number five Medvedev was also strong, winning four of five. Djokovic was his only conqueror, and only just in a high-quality three set semi-final. "I think I'm not that far," last year's US Open finalist said of the gap between him and the Serb.
Why not women?
If an early-season team event is good enough for the men, then why not women as well?
Djokovic said he supported the idea, as did former US Open runner-up Madison Keys after scathing criticism that women had been sidelined at the WTA Brisbane International.
The event was played at the Queensland Tennis Centre, the same as the ATP Cup, but the men monopolised centre court with women relegated to outside courts.
Maria Sharapova said it felt like a "second-hand" tournament while Sloane Stephens, who is on the WTA players' council, complained that women players "weren't in the conversation to even be considered" for the main court.
Tennis officials scrambled to limit the fallout and insisted they were working on a "new concept" for women in the Australian summer.