Summer after summer, at the court or sitting at home watching on TV, you become accustomed with the sponsors of the Australian Open.
However, there was a new sponsor in 2019, and it's been around ever since and is back in 2023.
What the blinkin' hell is 1573, you've been asking?
Back in October 2018, tournament officials announced one of the biggest sponsorship deals in the Australian Open's history, with Chinese Baijiu distillery Luzhou Laojiao becoming an associate sponsor of the tournament for the next five years.
They've even got their own court at Melbourne Park after Court 2 was officially renamed to '1573 Arena' in 2019. 1573 logos are also prominent in signage around Court 3 as well.
An uncovered court, 1573 Arena is one of the most popular sports to watch tennis at Melbourne Park and has some great views over the city.
Considering the Australian Open is also billed as the Grand Slam of Asia/Pacific, it's no surprise another major Asian brand wanted to buy into the biggest sporting event being held in the world right now.
Notably, Korean motor company Kia - which is the major partner of the Australian Open - has sponsored the tournament since 2002, and enjoys a long term partnership with 22-time Grand Slam champion Rafael Nadal.
In 2018, Tennis Australia also signed a five-year commercial deal with Chinese water company Ganten.
However, Luzhou Laojiao is one of three associate sponsors, alongside bank ANZ and watchmaker Rolex.
There are several partners , including Emirates, Accor Hotels, Barilla, Aperol and Blackmores - and some obscure ones you have probably searched online, such as ice cream brand Häagen-Dazs, information technology consulting company Infosys, and luxury furniture company De Rucci.
However, with Luzhou Laojiao one of the big four in Melbourne, they get priority signage spots, including coveted corner signage showcased on Rod Laver and Margaret Court Arena.
If you're also wondering what's missing, wine brand Jacob's Creek ended their association with the tournament after 13 years with the Australian Open.
As soon as players on the main courts win their match, 'Congratulations' is beamed on the digital boarding, along with Mandarin Chinese.
But why 1573? What the hell is 1573?
Simple - the history of the distillery dates back to 1573 in the Ming dynasty, making it one of the oldest Chinese liquors still in production.
At a function in Shanghai in October 2018, Tennis Australia’s chief revenue officer Richard Heaselgrave said the deal with Luzhou Laojiao was "one of the largest deals that Tennis Australia has ever negotiated" - but refused to disclose the value of the deal.
Reports suggested Tennis Australia officials were confident it was indeed the biggest sponsorship signing an Australian sporting body has confirmed with a Chinese business.
That's saying something. Prior to the 2018 tournament, a new five-year contract - reportedly worth in excess of $85 million - was announced with Kia.
The other two associate partnerships, Rolex and ANZ, are respectively worth $10m and $7m annually.
According to a report by The Australian , the partnership with Luzhou Laojiao is the second phase of a long-term strategy Tennis Australia has in China, with the governing body aiming to double the broadcast hours beamed into China over the next two years.
Tennis Australia also hopes to bring more visitors from China to the tournament after the Australian Open experienced a rise of 48 per cent in foot traffic in 2018.