High school coach here of 800 meters (1:55- 2:05 range) and 1600 (4:15-4:40) boys. We have a tried and true workout that seems to be a good indicator of race times. Its basically the 12 x 200/400 rule. In other words, if an 800 guy can do 12 200s at 30 seconds, he can run a 2:00 half. If a 1600 guy can run 12 400s at 70 seconds, he's a 4:40 guy. Not exactly a perfectly formula (and the 400s workout is a bit tougher) but has worked really well for my guys.