Vertical Jigging Deep!
When trolling yields eaters but the average size isn’t increasing , consider vertical jigging!
You can use lures such as Berkley Finishers, Rapala Jigging Shadow Raps, Berkley VIbratos, Ripping Raps, Northland Puppet Minnows.
Find saddles, humps, holes, any structure that is a classic walleye slip bobber spot. Spot lock over it, drop the jigs, and give it an hour. See how many bites you get. If you get a few hard hits but no hook ups, try changing to a different lure and see if you star hooking them. It can be hard to understand why a certain lure keeps missing fish, but sometimes just changing lures can make or break a trip.
Often times on saddles and other “highway” areas, the fish will be zipping by very hungry, and will often strike before you can mark them on 2d sonar / downscan. Lazy fish on humps and holes can sometimes circle the lure and you will mark them over and over and over until you get that hit. If I’m on a saddle or highway area and noticing a lot of lazy fish, it usually means a slowed down, less aggressive tempo will seduce even the weariest fish. If a decently sized lure keeps catching small walleye, upsize! The fish are telling you what they want, weed out the small ones and use a big bait!
I will always stand by the statement that long lining puts the most fish in the boat, but lately vertical jigging deeper structure has been putting larger fish topside!