They weren't quite playing the lottery as much as they were taking stacks of tickets and scratching them all off one by one to find something that looks like it might be a winner. This was very hard work. 100's or even thousands of samples.

> Would be wild if some impurity is what pushes it over the edge to a full blown super conductor.

I already mentioned this in another comment, but x-rays and radioactivity were discovered in that precise way.