Jakob does not have any world junior record, he is very far from them. And none of the world junior record holder have set a senior record later except Shaeen. So you expect him to be a late bloomer when he is an early bloomer.
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Do you have a master degree in logic?
You blame Jakob for not having a World Junior Record and simoultaneously state that none junior WR holders get WR´s. So why should Jakob care?
By the way : Kenenisa Bekele held a U20 WR in the 3000m. Did you forget him?
Early bloomer:
I have made a little bit research about former and current 800m/1500m runners to see how they developed from their teens in the 800m:
Steve Ovett. age 17 1:47.34; age 22 1:44.09
Seb Coe. age 20 1:44.95; age 24 1:41.73
Steve Cram. age 20 1:46.29; age 24 1:42.88
El-Guerrouj. age 20 1;47.18
Marcin Lewandowski. age 17 1:51.73; age 19 1.46.69; age 28 1:43.72; age 32 1:43.74
T. Makhloufi. age 21 1:49.40; age 28 1:42.61
Centrowitz. age 20 1:51.40; age 25 1:44.62
Elijah Manangoi. age 22 1:47.40; age 25 1:44.15
Craig Engels. age 16 1:55.37; age 19 1: 51.03; age 25 1:44.63
Jake Wightman. age 18 1:52.16; age 19 1:48.01: age 24 1:44.61
Timothy: age 18 1:45.92; age 23 1;43.11
Kalle Berglund. age 16 1:58.39; age 19 1:46.85; age 22 1:46.63
Drew Hunter. age 16 1:59.55; age 18 1:48.64; age 20 1:48.57
Josh Kerr. age 16 1:53.80; age 19 1:48.05; age 21 1:45.35
Jakob Ingebrigtsen. age 14 1:52.60; age 15 1:51.07; age 16 1:49.40; age 19 ???
As you can see runners normally develop substantially up into their twenties some even into their late twenties.
BUT YOU WILL PROBABLY SAY THAT THEY ARE JUST EXTREMELY LATE BLOOMERS ALL OF THEM?
AND MAINTAIN THAT JAKOB IS JUST AN EARLY BLOOMER WHO IS GOING TO PEAK SOON?