Serbia won the inaurugal ATP Cup. (Getty Images)

The inaugural ATP Cup is over with Serbia defeating Spain in the final. Now that the madness has come and gone, it's time to look back at five takeaways. 

1

New innovations

If there is one thing tennis is slow on, it's innovation. The ATP and WTA largely prefer to keep traditional rules in place, rather than change what isn't broken. Tradition is wonderful, but the ATP Cup showed what the future of tennis could look like.

On-court coaching, team zones in the corners of the courts, and real-time statistics were just the tip of the iceberg. It's not quite at the level of the Next Gen ATP Finals, but it was still a change. 

2

Novak Djokovic is on fire

While the Serbian may not be world No. 1, he showed he's the one to beat in 2020. He won both his singles match, over Rafael Nadal, and the doubles decider to clinch the ATP Cup title for Serbia. It's just the warm-up he needed ahead of the Australian Open, though it forced him to withdraw Adelaide. 

The world No. 2 went 6-0 across the team event, and earned 665 points, putting him just 515 points behind Nadal.

3

Alexander Zverev continues his 2019 woes

If fans of the German were hoping for fireworks at the start of the season, they will have to keep waiting. Zverev established himself at the top after winning three ATP Masters titles and the ATP Finals across 2017 and 2018.

Last year only saw him winning a title in Geneva and losing in the first week of three of the four majors. He was inspired at the Laver Cup by his Team Europe teammates, but the ATP Cup team atmosphere didn't have the same effect. He lost all three of his matches, while hitting 31 double faults. He was even stung by a bluebottle jellyfish while swimming at the beach.

Hopefully it won't be an omen for 2020.

4

Season dark horses emerge

Besides the obvious Djokovic and Nadal, some players stood out during the tournament, including Roberto Bautista Agut and Daniil Medvedev, emerging as early-season contenders for the Australian Open.

Agut, who saw a great 2019 season by making it to the Wimbledon semifinals and breaking into the Top 10, got through the ATP Cup unbeaten, winning all six of his matches. Since the ATP Cup awards points based on ranking of opponent beaten, he picked up just 305 points.

Medvedev almost went unbeaten as well, winning four out of five matches before being taken down by the Djokovic in the semifinals.

 

5

A WTA Cup

With all new tournaments, there was controversy surrounding the ATP Cup. Along with the points system, and the leaving out of many top players, the ATP Cup's Queensland Tennis Centre was the same venue as the Brisbane WTA International. As the ATP Cup took center court, the women were relegated to the outside courts, and the field included world No. 1 Ashleigh Barty. 

The answer? A WTA Cup. The likes of Djokovic and Madison Keys have supported the idea and, supposedly, plans are in the works.