To say Novak Djokovic has had an eventful start to the 2022 season would be about as big an understatement as you could imagine in tennis right now.
Djokovic was not allowed to defend his Australian Open title, deported from the country, and now has publicly stated he is willing to miss any tournaments he has to in order to remain unvaccinated against Covid-19.
That means his world number one spot is now in huge danger, and he could even lose it to Daniil Medvedev this week.
Planet Sport takes a look at the situation and the various scenarios that could see the Serbian relinquish his place at the very top of tennis.
How do tennis world rankings work?
Players are awarded ranking points for their performances in tournaments across the year, with more points awarded for the higher level of event you enter.
Grand Slams are top of that tree, with 2000 points available for the winner, then comes Masters events which award 1000 for the winner, while ATP500 and ATP250 tournaments give a maximum of 500 and 250 points respectively.
The ATP Finals is slightly different in that it is an invitation only event. There are up to 1500 points available to the winner depending on how he performed in the round robin stage.
Points that are won last for one year in the rankings before they drop off, meaning players are essentially always 'defending' their points from the previous season.
For example, at the recent Australian Open:
Aslan Karatsev reached the semi-finals in 2021 but only the third round in 2022, meaning he lost ranking points.
Stefanos Tsitsipas reached the semi-finals in both, meaning he retained his ranking points.
Rafael Nadal reached the quarter-finals in 2021 and then won it in 2022, meaning he gained rankings points.
The waters this year are slightly muddied by the fact the Australian Open was delayed by a couple of weeks last year, meaning players currently have the points from both the 2021 and 2022 events, but that should address itself next week when points from the 2021 Australian Open expire.
The state of play right now
The current ATP rankings can be found here, although they are perhaps not the best representation of the current state of play.
Instead, here is the projected rankings from next week (w/c February 21) which includes the dropped points from the 2021 Australian Open.
1 - Novak Djokovic 8875pts
2 - Daniil Medvedev 8435pts
3 - Alexander Zverev 7515pts
4 - Stefanos Tsitsipas 6565pts*
5 - Rafael Nadal 6515pts
6 - Matteo Berrettini 4843pts*
7 - Andrey Rublev 4385pts*
8 - Casper Ruud 3975pts*
9 - Felix Auger-Aliassime 3778pts*
10 - Jannik Sinner 3429pts
(*Total does not include points from Marseille and Rio for w/c February 14)
Due to emergency Covid-19 rankings system complicates things further, with the ATP temporarily moving to a two-year cycle for retaining points to help players protect their ranking during the pandemic.
Many of those points will also gradually drop off the player's totals as we move through 2022.
How significant would Novak Djokovic losing world number one be?
In a word, very. In any other era, the world number one changing hands was not especially unusual, but this is not just any era.
This is the era of the 'big three,' and since 2004 Andy Murray is the only man not named Roger Federer, Rafael Nadal or Novak Djokovic to top the rankings.
That means that in the 31 years before 2004, there were 22 men who reached world number one, and in the 18 years since just four men have. Remarkable.
Medvedev is attempting to muscle in on the big three dominance and should he be able to do it he will be the third Russian man to do it after Yevgeny Kafelnikov (1999) and Marat Safin (2000-01).
There also needs to be a special mention for Djokovic in this. Trying to take the world number one spot from Roger Federer or Rafael Nadal is hard enough, but taking it from Djokovic has proven nearly impossible.
Whatever happens, Djokovic is guaranteed to have spent 361 weeks at world number one, which is 51 weeks more than his nearest rival (Federer).
How Daniil Medvedev can become world number one this month
The ATP rankings are fluid and often difficult to track, particularly as it transitions back to a one-year cycle, but ultimately it is Daniil Medvedev who has the power this week.
The two are not in direct competition next week, with Novak Djokovic playing Dubai and Medvedev playing Acapulco.
Therefore, there are six scenarios in which Medvedev can displace Djokovic as world number one. Deep breath...
- Medvedev wins the Acapulco title, regardless of Djokovic's results in Dubai
- Medvedev reaches the Acapulco final and Djokovic does not win the Dubai title
- Medvedev reaches the Acapulco semi-finals and Djokovic does not reach the Dubai final
- Medvedev reaches the Acapulco quarter-finals and Djokovic does not reach the Dubai semi-finals
- Medvedev reaches the second round in Acapulco and Djokovic does not reach the Dubai semi-finals
- Medvedev loses in the first round in Acapulco and Djokovic does not reach the Dubai quarter-finals