World Number 1 Jason Day is determined to retain his place on top of the world but it could change this week.

Jason Day Day spoke ahead of his title defence at the PGA Championship of his desire to finish out the year as the World Number 1.

However he will need to ensure he plays well this week to prevent U.S. Open Champion Dustin Johnson overtaking him.

"I really want to finish No. 1 in the world at the end of the year. But I think the biggest thing for me is to really understand what I need to do to win each week or get myself into contention," said Day.

"Winning takes care of everything. I think that's probably more concerning for me is I just need to feel, even though I'm comfortable with winning, I need to get back to the point where I feel like I go out there and win every single week."

"I really enjoy being up at the top of the World Rankings and I really want to see how far I can take myself in my career to see how long I can hold it there."

The OWGR ranking for the 98th PGA Championship stands at 923 which ties the highest ever achieved by an event in the history of the Official World Golf Ranking.

As with all Major Championships the winner will receive 100 OWGR Points.

The 94th PGA Championship won by Rory McIlroy at Kiawah Island Golf Resort also had an OWGR Event Rating of 923.

Here are some scenarios that relate to the OWGR Top-5 and the 98th PGA Championship starting at Baltusrol tonight:

Dustin Johnson will go to World No 1 by finishing 2nd alone provided Jason Day finishes lower than 28th alone.

Dustin Johnson will go to World No 1 by winning  provided Jason Day finishes lower than T2 with 1 other.

Jordan Spieth will go to World No 2 by finishing T2 with 1 other provided Dustin Johnson finishes outside the Top 22.

Jordan Spieth will go to World No 2 by finishing 2nd alone provided Dustin Johnson finishes lower than 10th alone.

Jordan Spieth will go to World No 2 by winning provided Dustin Johnson finishes worse than T2 with 1 other.

Rory McIlroy will go to World No 3 by winning  provided Jordan Spieth finishes worse than T2 with 1 other

Henrik Stenson will go to World No 3 by winning  provided Jordan Spieth finishes outside the Top-15

Henrik Stenson will go to World No 4 by finishing 6th alone provided Rory McIlroy misses the cut

Henrik Stenson will go to World No 4 by finishing 5th alone provided Rory McIlroy finishes lower than 33rd alone

Henrik Stenson will go to World No 4 by finishing 4th alone provided Rory McIlroy finishes worse than T14 with 1 other

Henrik Stenson will go to World No 4 by finishing 3rd alone provided Rory McIlroy finishes worse than T6 with 1 other

Henrik Stenson will go to World No 4 by finishing 2nd alone provided Rory McIlroy finishes lower than 3rd alone

Bubba Watson will go to World No 5 by winning  provided Henrik Stenson  finishes worse than T6 with 1 other

Check out the current top-25 players in the world.