I prefer shiners 6" or a lil bigger, but I'm with Jim, they don't have to be huge to catch big fish. My biggest pike this year (nothing huge, just 31") was caught on a dinky 2-3" shiner. I also caught a 12" pike on a 6" shiner, the flag went off 8 times before he was finally able to get the minnow in his mouth past the hook. Obviously a bigger minnow is more easily seen, but if the fish is hungry and sees it, it will eat it. This time of year, late in the season, the minnows from the bait shops seem to get smaller and smaller, but I usually catch the most fish, and the biggest, at the end of Feb and early March. If the fish are active, it won't matter a whole lot.
Countdown to 2011/2012 Ice Fishing Season: ?????