Some of the tests I have set.
Top shot, long mark was the go-bird, and the short the memory. dogs who failed the blind squared the shore and got out early and then ran around in the tall cover back on land.
Next, the memory bird was the longer mark with the land entry and then down the channel. A lot of dogs cheated it and ran deep on land which did not help them as the wind was blowing from land to water--no wind saves, no reward for cheating. This was the mark that most dogs who failed could not do--the "money" bird. The water blind was in running water, but full of dogwood and other scrub, and we lost a couple of dogs there as well who became self-employed..
In the third, the dogs did the marks fine for the most part, but on the blind some scalloped back to shore all the time with the tighter entry, or else got fixated on the islands and refused to cast into the corner where the bird was.