It's 50 bonus stamina added at the end of 2 hours. The 2 hours can be divided into any number of sessions you want. There is no randomness involved at all.

If you do not have a medal, you ALWAYS get +50 it at the end of 2 hours. You get 40 stamina from the spring, 20 stamina from natural regeneration over the 2 hours, and 50 bonus at the end, for a total of 110 stamina.

If you have a jonin medal, you NEVER get it at end of 2 hours. You get 60 stamina from the spring, 20 stamina from the natural regeneration over 2 hours, with nothing at the end, for a total of 80 stamina.

So you actually recover less stamina with a jonin medal if you use up the 2 hour limit completely, compared to a player who does not have the medal. This post was last edited by IamAscrub at 2017-3-15 06:15

I watched the timer expire for 4 weeks straight, it happened every single time. Have you actually tried to set *arm 1 minute before it expire and watch it?