GFIs1 DAX System

Over the years I used to occasionally read the journal by GFIs1 where he made one DAX trade per day. I see that it was removed last year and he is no longer on this site.
He had a set of rules which I didn't understand that well.
I recall he would enter long or short at a certain time in the morning and hold for a predetermined number of hours. I think his Stop Loss was usually around 40 points.
The decision to go long or short seemed to be based on historical data for each day of the week and maybe on the direction of the the first 30 minute bar (???). There were often days where he would take no trade, but I didn't understand his reason for that.
Does anyone here know his system / rules ?
He was quite open about it so I don't think it would be an infringement to share any details.
-- Thanks.