When he was younger (until 15) he competed in all events (track and field events). During late high school, he focused on 400/800, getting to 51 and 1.59 at age 16 off 12 weeks training per season (week consisted of 150s, 300s, race day). Had a year break after HS.
Past two years has come back, but focusing on "longer stuff" as he had never trained properly as a MD athlete. This means although he has been training serious, his mileage is low and everything (tempos etc) are fairly new to him. His 400 time is slower (52/53 off no speed training) and his 800 time dropped by a few seconds (1.56). 10 000, 5 000, 3 000 times are nothing to write home about.
The question is, how do you know if he is a 800/1500 runner, or a 1500/3000/5000? Showing potential in all but potential definitely has not been reached in any.