hyphothesis:
the system only saves your current stam when you make a kill (or get beaten up) and when you enable berserk.
it does an on the spot calculation to find out your exact stam.
e.g. you make a kill at 10:00, leaving you with 15 stam. the system saves that number and the timestamp, 15 stam at 10:00.
as the clock runs, it makes an on the spot calculation. time is 10:45, last kill at 10:00 with 5 stam,
stamina at 10:45 = 15 stam last saved + (75 base*(1 + 0 berserk multiplier bonus) + 25 from accessories))/hour * 0.75 hours = 90 stam.
but this value does not get saved until you make another kill which saves your current stam and the timestamp.
but there is a bug when enabling berserk and at the end of berserks that does an inaccurate calculation. (i think is that of emerald rings but not exactly sure).
enabling berserk:
berserk enabled at 10:45,
save : stamina at 10:45 = 15 + (75 base*(1 + 0 berserk multiplier bonus) <accessories missed out>))/hour * 0.75 hours = 71.25 stam
or some other miscalculation.
end of berserk:
last kill at 10:00 with 15 stam, berserk ending at 10:15,
should be: berserk ended,
stam at 10:15 = 15 + (75 base*(1 + 5 berserk multiplier bonus) + 25))/hour * 0.25 hours = 133.75 stam
miscalculation:
stam at 10:15 = 15 + (75 base*(1 + 0 berserk multiplier bonus) + 25))/hour * 0.25 hours = 40 stam
conclusion:
to prevent miscalculations, make a kill before you enable berserk if you have left it running for quite some time,
and make a kill just before your berserk ends (does not have to reach 0) to minimise stam loss.
side note:
more complicated calculations takes place when your stam transitions to 100 where the base stamina regen decreses from 75 to 55.
