Karsten says he can be competitive with Jakob in the 800m in this interview recently.

Back in the dy, Moses ran 1:48.xx, and Harold Schmidt ran sub 1:45 (if memory serves). KW is much better than than either of them both in bestperformance and volume of performance. If he had a mind to, I can't see wht he couldn't go sub 1:45 as well...

Laros is much more talented at 800m than Jakob, he’s a future 1:42 guy, Jakob’s amazing but he doesn’t have that 800m ceiling

One could agree with you, because:

1. Jakob’s 800m pb of 1.46.44 is less than half a second from sub 1.46. Given his progression in the 1500m he might also progressed some in the 800m, but we just don’t know what he can do unless he races the distance again (meaning under the same conditions as in his pb run).

2. Your estimates of Karsten Warholm seem quite fair (10.20+-, 1.48-1.52), but there’s a problem here: Would you have given the same 800m estimates based on his 2017 pbs?! This question is extremely interesting, because Karsten has obviously progressed in all his events since then -but based on your reasoning I suspect you to give him worsened 800m estimates 2023 than you would have given him based on his 2017 results..!

Karsten’s 2017 pbs: 100m 10.49 (indoors), 200m 20.91 (indoors -would probably been faster outdoors because of the less sharp bend), 400m 44.87 (outdoors), 400mh 48.22. He has no adult 600 or 800m pb…. So what would the reasoning been based on this? Would you have gone for something like this:

Obviously not a fast sprinter type, but more of a strength 400m / 400mh guy (obviously significantly better in the 200m, 400m / 400mh than in the 100m), and therefore better in the 600m and even 800m than almost every other 400m / 400mh guys…! Clearly sub 1.48 capacity; maybe even sub 1.45…. (And maybe you even make a comparison with Rai Benjamin -1.22 in the 600m as 16 year old, and maybe good for sub 1.18 based on his progression in the 400m. But he’s a fast guy -10.03 and 19.99 in a headwind. So a much slower guy (Karsten 2017) should do an even better 600m -can there be something right in the rumours about his 1.15 training time trail..?

My point is: Would you give Karsten Warholm a worse 800m estimate today than you would have done in 2017, based on his bettered 100m time? And what about the reports about his “new” (post 2017) strength training -long threshold interval training. And his own words about maybe having world class 800m potential..?

Has his progression last years lowered his 800m potential (according to your “too fast 100m speed logic”..?)

Warholm wasn't really better in the 200 than in the 100. 10.50 and 21.0 are about equal.
Also, his 100/200/400 PR have improved in a linear way rather simultaneously. As mainly a 400/400h, he has always been better in the 400 than in the 100/200 but not by a huge margin. 10.5/21.0/46.1 isn't like 10.5/20.7/44.5 and that's still not a indication for a great 800, just a normal pure 400 runner (like Borlee, Djhone etc). For sure he is not a Kerley type of sprinter but that still looked more like a speed guy than a strengh guy to me. Also the 2:45 1000m tells something. If he had a great 800 ability, I think you would see something suprising there for a multi event athlete like 2:30-35. I also take visual impression into account. Based on his stride, he seems powerfull and a sprinter rather than a smooth strengh guy.

All this considered, I would have probably said that he wasn't a potential fast 800 runner back then and gave him something like a 1:51-55 ability.

It's true that his training seems to be a good point for a good 800 and that's why I can see him run maybe 1:48. But that's the only pro compared to all the cons. I don't give a lot of credit to what he says he is able of in the 800 as he has never raced the distance, and I feel like he is overconfident (common among sprinters) or half joking there.

So name another double Olympic or world champion over those distances since then.

You could say that about any great 400m runner. It doesn't turn them into a great or even respectable runner over twice that distance. Very few manage it. We've seen no indication that Warholm is one of them.

It's what happens on the second lap that determines whether he could run a good 800. Most sprint-based athletes (which is the 400 and below) can't.

You didn't say double champion, you said that could compete at the top.

So good at an event he never competes at. Makes sense. The 400 or 400h is not an endurance event, so we don't know what he has of that. The 800 requires it.

At the top in both events means at least be in championship finals in both. Juantorena is the last who showed he could be the best over both distances - nearly fifty years ago. It's a rarity now - because the events are actually quite different.

Jakob has astonishing endurance but speed - which the 800 requires - is not one of his attributes. I doubt he has more speed than Lagat, who said 1.46 was about his limit.

I think it's also worth mentionning the way Warholm run his 400/400h, i.e. very fast from the start.

Marc Raquil, for example, a 21.03/44.79 guy, who was famous for training with 800 runners in the winter, had a very different style.

The french commentator says after 100m when Raquil is dropped "he is going to do his special last 100, I know it, I feel it" then in the last 50m, dispappointed : "it's too far, it's too far...OOOOH it's not too far!"

Would you say Rai and Alison are doping too? I'm typically on the everyone is doping train and I won't say they're all super clean, but the times are more believable than we should think. Typical 400h guys are 45/46 open guys who make the move. A 44 guy (possibly 43 shape) with the right form and stride should be able up run 46

I think it is possible Karsten could be competitive with a few months of 800m specific training. 400H runners can be real solid in the 800m. EX: UW has has a solid 400h runner, Cass Elliot, who has prs of 49.13 for 4hurdles and 1:46.76 for 800m (indoors). Possible Warholm could be a 1:44-45 guy; however, far more likely he would run 1:48-51 and never try again, sorta like Wariner

Brandon Johnson. Dropped the 400h and ran 1:43 800

It is a bit different if he would spend time training for it. Rolling out of bed tomorrow something like 1:48 would be my over under line. Maybe he drops a 1:45 but I doubt it. It would help a lot of there was a good pacer (on his own he might go out in 49...).

Train for the even then I think 1:45 starts looking pretty reasonable. But few 400m guy ever do something like that...

Karsten can barely break 45 in the 400m and his raw 200m speed is quite slow for his 45.94 time, he's clearly more a slow twitch runner than 90% of all the elite hurdlers

And how many thousand 400/400h runners have there been that don't - can't - do anything over the 800? The chances are therefore against Warholm being one of them - unless he demonstrates it. So far, all he's offered is talk.

Slower doesn't mean he has the endurance of a md runner.