Faith Kipyegon showed with her 5000m world record earlier this year that she doesn't fear the unknown.
She had raced just twice over the distance before that, some eight years prior. But she took on - and ran away from - a quality field to set her second of three track world records this year.
Now, despite having never raced on the roads, the Kenyan great turns her attention to the mile at the World Athletics Road Running Championships Riga 23, where she is aiming to win her third global title of the year, following the 1500m and 5000m golds she earned in Budapest.
The 29-year-old has already shown versatility across different terrains, as well as distances. Back in 2011, she won her first global title in the U20 race at the World Cross Country Championships, which she successfully defended two years later.
The track has been her main focus in recent years, but she has often spoken of a potential move to the roads - and eventually the marathon - so her appearance in Riga marks the first significant step in that plan.
Her track mile world record of 4:07.64, set earlier this year in Monaco, is seven seconds faster than the PB of the next-fastest entrant. It's also 20 seconds faster than the newly ratified official road mile world record (4:27.97), which belongs to USA's Nikki Hiltz.
It's probably safe to assume that the winning time in Riga will fall somewhere between the existing world records for the track mile and the road mile. And while it would be brave to bet against Kipyegon, there is never a guarantee in sport - especially with a field as good as the one in Riga.
Ethiopia has selected three of its best middle-distance runners, all of whom have bettered 3:56 for 1500m this year.
Diribe Welteji was Kipyegon's closest challenger at the World Championships in Budapest, finishing within one second of the Kenyan to take silver in 3:55.69. She went on to set a personal best of 3:53.93 at the Wanda Diamond League Final in Eugene, once again finishing second to Kipyegon.
Kipyegon won't be alone in her quest to secure a medal for Kenya, as she'll have support from compatriot Nelly Chepchirchir. The 20-year-old has been a revelation this year, breaking 4:00 for 1500m on five occasions, placing fifth at the World Championships, and clocking a PB of 3:56.72.
World 3000m steeplechase record-holder Beatrice Chepkoech had also been entered, but is a late withdrawal.
The fight for medals won't be an all Kenya-Ethiopia affair, though.
World under 20 1500m champion Reynold Cheruiyot has used the 2023 season to test the waters of the senior international scene. He now aims to end the year by winning his first senior global title.
The 19-year-old Kenyan won the world U20 1500m title last year, which he followed with silver in the U20 race at the World Cross Country Championships in Bathurst back in February. He won the African U20 1500m title two months later, but has focused on senior competition since then.
He clocked a 1500m PB of 3:30.30, putting him fifth on the world U20 all-time list, and came close to matching that time when placing eighth in the World Championships final in 3:30.78.
After the World Championships, he went on to set a world U20 best for 2000m (4:48.14) and a world U20 record for the mile (3:48.06).
Not only does he have the fastest 1500m season's best of all the Riga entrants, he also has the fastest track mile PB. But even so, there is no clear-cut favourite in this extremely open field.