Dwarven Guard - Regarding Evil Players

[Fermouth]

So I had a conversation with DC regarding the calculations of dwarven royal guard and their between rounds spell of yell for aid.

He says I'm retarded and blah blah blah. 
But I'm pretty sure I make sense to myself. Heh.

But here is what I think.

Between rounds spell is 20% according to MMUD Explorer.
I go into a room to buy something and get blasted by 19 dwarven guards.  In one round 5 aids were yelled out.
I gather this to be 36.8% roundabouts.  Which to me seems 16.8% above what it should.

After talking with DC, he claimed it was because of the TIME factor...

This makes no sense to me.
After all, for every five rounds, a dwarven guard should yell for aid 1 round.  Right?

Also, shopkeepers should yell for aid 100% of the time between rounds.

[Gardner Denver]

I'm pretty sure that the way gmud handles this type of thing that 20% != 1 in 5 chance. 

What is most likely happening is each guard has a 20% chance per round.  So you might see doubles, trips, etc.  But it is not a "ok I cast it this round so I won't do it for the next 4 rounds" any more than a 20% item drop happens every 5 kills.

[Thesifer]

Just as in real life..  20% doesn't translate directly to 1 in 5.  It never has.  That's "Theoretically" what will happen over a period of time though.