I have had 3 great trips in a row this month fishing perch with tip-ups here in NY. Have caught 25, 31, then 20 and almost all were 10" plus, one 13 incher. What bait did I use? 2-3 inch shiners ( emerald I think, but this is probably irrelevant ) fished exactly 1 foot off bottom in 20' water.
The lake is fairly good-sized, a few thousand acres. As with most lakes this large and bigger, the 20' depth seems to be the preferred hangout for the jumbos. There is also an inflow from a brook not too far away. Bottom line for locating jumbos is that your 3 inch shiners will be taken by only the largest perch in the lake. If like some people, all you do is jig with small baits, you may or may not catch the jumbos. The bottom line, in my opinion, to quickly determining how big the perch can get in your lake, is to set out the tip-ups.
I spend very little time jigging when I am getting a lot of action on the tip-ups, because I know that every time I get a flag it is almost certainly a 10" plus fish. Also, I have perfected the art of running to every flag with bait pail in hand, quickly getting the hook out with needle-nose pliers, and returning the minnow ( either a new one or keep re-using the same minnow as long as it is alive ) back down to the marked depth ( split shot on the line ). I am very fast at re-setting a tip-up, man! Practice this, and I think you'll agree it is a great way to catch a lot of jumbo perch, and something about seeing flags go up always adds an element of excitement that jigging can't match.
Last but not least, the tip-ups always give you a good chance at the incidental catches of bass, walleye, trout etc. depending on what's in your lake. Good luck with your fishing, dude.