Sydney is most certainly capable of running 48.5-49.0 open right now over 400m. She's about to break sub 51 in 400h at worlds.
With some proper speed training she can dip under 48.5. 47.6 is a stretch but it will be fun watching her go for it.
A few stats for helpful context....
- 4 years ago when she was running almost 1.5-2 seconds slower over 400h, she ran 50.07 in the open 400m in MARCH as a Freshman at Kentucky to open her outdoor collegiate season. She ran this in the pouring ran, btw.
- In the same meet, she ran 22.39 over 200m (not a bad double)
- She ran 50.38 indoor that same year as a freshman at Kentucky
- She ran 2 sub 50.0 splits FAT in HS
- She ran 48.8 split on the 4x4 at 2019 worlds
- She was the lead-off lead at Tokyo which is why she didn't dip below (she looked way too comfortable and didn't go out hard enough as she clearly needs more reps in the event)
I strongly believe she has 50.6-8 400h potential this year. Once she gets that 400h record in a place that won't be touched for a few decades, she will move over to the open 400. Throw in some speed training with Bobby over 100 and 200, she will be ready to challenge the 400m WR.
If she makes the pivot this summer after Eugene to the open 400, I bet we see 48.9-49.1 open and 21.7-9 over 200m