I haven't heard that story before about Fred J. throwing a stone into the swim to wake a pike up.
When I was secretary of a club we had a small pit that was half filled in with inert waste in 1989 and for quite a while the general fishing picked up because the water was cloudy with algae from the new nurtients. Eventually it cleared and around 1997 I noticed in one swim a half buried car, an old Vauxhall I think.
I could see that the windows had been smashed and wondered if anything lived in it so I found a spare lump of concrete and threw it on top of the car. The sound was surpressedby the water, but a pike or what looked aroun 8 or 9 pounds came flying out, bit hard to see because the ripples cause when the concrete hit the water were still dispersing.
I kept on working a spinnerbait over the area and suddenly latched into a pike, guess what, around 8½lbs. I didn't weigh it, just slipped it back whereupon it went back to the car. It took a look, but must have thought better of it and sloped off into deeper water. I thought at the time it was a strange coincidence.
The car's still there.