Ronnie O'Sullivan will have to claw back £326,000 at the World Snooker Championship to catch Mark Allen and end the season as the world No 1.
Snooker rankings are based on prize winnings from the previous two years with O'Sullivan currently out in front, largely due to his win at the 2022 World Championship.
However, the £500,000 prize he picked up for winning his seventh world title will be taken off after this year's event.
That puts O'Sullivan on just £609,000 prize money won for the two years after his last world title and provisionally fifth for the end-of-season list.
Ronnie O'Sullivan is provisionally ranked fifth in the world rankings
GETTY
Mark Allen is the biggest benefactor from the results of the 2022 World Championship coming off as he loses just £30,000 and currently sits on top.
Judd Trump is second as he will have his runner-up prize of £200,000 taken off with Luca Brecel and Mark Selby ranked above O'Sullivan.
The quintet along with Ding Junhui and Mark Williams will all have a chance at ending the season as world No 1 heading into the World Championship.
For O'Sullivan to end the season on top of the rankings, he'll have to win the event and rely on neither Trump or Allen making it through to the final.
It looked likely to be a sixth title of the season for O'Sullivan at the Tour Championship over the weekend, but he was resoundingly beaten by three-time world champion Williams.
O'Sullivan was full of praise for the Welshman after the final and tipped him as a strong contender for the 2024 World Championships.
"I think Mark has been the most consistent player for the last five years," O'Sullivan said.
“The way he has been hitting the ball. Very rarely does he play a poor match.
“The way he has played this week and in the final, he’s such an amazing player. He’s so talented.
Mark Williams is also a long shot to end the year as world No 1
GETTY
“I think he’s better now than he has ever been to be honest with you. He seems so strong.
“I tried, I gave it everything, but he’s so consistent, so strong.
“If you don’t keep playing top-level snooker against him, he’ll just eat you alive. I think I did well to get five frames.”
LATEST SPORT NEWS:
Ronnie O'Sullivan must win the World Championship to end the season as world No 1
GETTY
O'Sullivan added: "If he was to dedicate his whole life to it, he would probably be number one in the world," he said.
"But he doesn’t – he likes to play golf and chill out, enjoy his life.
"He doesn’t do badly for someone that just plays about it in the sport."