3) Implement Half-Life DR using 72 hour news
a) Half life of 18 hours * Relative Hit Strength, minimum of 12 hours, maximum of 24 hours (see d for EXPRESS)
i) ex1. If you hit with an attacking force of 110% of a targets defence, the half-life is 19.8 hours
ii) ex2. If you fail with 90% the halflife is 16.2
b) Continuous DR formula: DR_MULTIPLIER = DR_HITS<13 ? MIN( 1, 0.1+((DR_HITS-13)^2)/135) : 0.1
i) This is a simple smoothed approximation of the existing DR schedule
c) Hits older than 72 hours are IGNORED
i) With the exception of ALL-SET COUNTRY:COUNTRY DR, which is calculated with a 168 hour halflife (1 week)
d) EXPRESS HALF LIFE IS DIFFERENT:
i) 8 hour half-life (base) for Express (min 6, max 12); 72 hour ALL-SET COUNTRY:COUNTRY DR halflife
e) Reintroducing the 1/10th chance hits for specials
i) These was only removed for performance reasons in the past

Tip: The DR contribution of a single attack is

0.5^(x/n)

where

x = Number of hours since the attack happened
n = The attack's half life in hours = 8*oversend factor

The attack's base half life is 8 on Express. This is multiplied by the Oversend Factor, which is usually at least 1.1 for successful attacks, at most 1.0 for failed attacks. No matter what though, n cannot go lower than 6 or higher than 12 for Express. If you like Excel or something, you can do the clamping of n to between 6 and 12 with one of the following:

=MEDIAN(6, 12, 8*oversend factor)
=MIN(MAX(8*oversend factor, 6), 12)

Now all the above are in hours, you can use minutes if you wish. x and n divide by each other and whatever time unit you want to use cancels out anyway.