Besides actually running 800m what is a workout that indicates sub 1.50 potential. I read on another website that the coach of Ricky soos says a good indicator is to run 2 400s with 45 sec rest and then have 20 mins rest and repeat. Add all the 400 times together and divide by 2 and apparently that is pretty accurate.
4x400 with 4min rest.
The same way you broke 2:00 flat. Just faster.
You don't need to be doing indicator workout in addition to racing. They serve the same purpose. Do the workouts that will help you the most physiologically to make that step. I would recommend one day a week of 5k paced intervals. A day of hill repeats with plenty of recovery, a tempo run/progressive run day + alactic hill sprints, and a long run. I would also recommend 150 accelerations after recovery days if you feel good. Just start out nice and slow, then by 50 meters into it you should be moving around mile race pace or a bit slower, then 50 meters later you should be around 800 race pace (approaching 400 race pace), then the last 10-20 meters go as fast as you can while remaining relaxed. Relaxation is key. Again, take 3 minutes rest between these just like you would between the hill sprints. Hit at least 50 mpw and you should be good. When you get closer to the end of the season, you can drop the progressive run and the hills in favor of races and specific workouts, but I would keep the 5k pace stuff. Best of luck. However, it seems as if you truly aren't asking HOW to break 1:50. You seem to want to know before the race that you are going to break 1:50...not sure why. Anyway, I would assume your coach is probably handling most of your training, but you can always make suggestions.