No more second guessing.

[Walleye Express]

Started out this morning headed for my spot on the 47's. Seen quit a few boats trolling in a tight group 2 miles SE of the Black Hole but still 4 mile South of my original destination. Slowed the boat down to have a look and the whole screen was full of fish from top to bottom. Put the lines out and started trolling with the waves, NE towards the end spark plug. Again, didn't have so much as a nibble for almost 3 miles until we hit that magic 21FOW. I understand a lot of things about what and why walleyes do some things, but I'm at a loss for this 1 foot difference making so much difference in the fish's biting attitude the last few trips out on a body of water this big. Does anybody have or can share some ideas about this phenomina? Oh , we boated 17 and kept 11 in the short time we were on the biting fish.