Will the men's 100m or 200m world records fall first?
There's only one man to answer that: the current holder of both records, the eight-time Olympic champion Usain Bolt.
Despite having been retired from athletics since 2017, the Jamaican still holds the title of "the world's fastest man": 9.58 seconds in the 100m and 19.19 seconds in the 200m.
"It's a great title," Bolt told World Athletics Inside Track. "It's something that I enjoy even if I say it's not the most important – it's always the (medals), but it's a great title to have.
"It's something I enjoy knowing."
So which record will go first? "Not worried about none of them," Bolt laughed.
"I really don't know, I think the 100m's going to be harder (to break) because it's quicker, and if you make a mistake during the race you're not going to get it.
"It's a lot more technical so I think maybe the 100m's going to go last."
United States sprinter Noah Lyles, the current world champion in both the 100m and 200m events, targeted Bolt's 200m 19.19 in 2023 but did not achieve his goal. The American's 19.31 national record remains the third-fastest time ever.
Reflecting on his 100m world record in Berlin in 2009, Bolt said: "I remember actually we had a bet: me, my coach and my masseuse, on how fast I was gonna run.
"I knew I was gonna break the world record because I was in such good shape at the time. I was running great throughout the season."