Hello Mr. Lincoln,
In some lakes, like Dauphin lake, Walleye rarely attain large sizes despite growing quite old. Our test netting has shown that some of the Walleye we catch are up to 16 years old - which is fairly old for Walleye in Southern Manitoba. Yet these old fish were only around 60cm (24") in length. For comparison, the large fish (over 28") on Lake Winnipeg are usually age 10 to 12.
Sometimes lake specific size classes are due to genetics (we think), sometimes it is due to a lack of big nutrient-dense prey like Cisco, (we think), sometimes it is because of density issue (lots of medium and small sized fish competing for the same food which makes all of them grow more slowly (we think), ...or it could be a combination of these three - or other factors that we just don't understand!
Some lakes produce numbers, some produce giants, rarely do they produce both. In Manitoba, we are so fortunate to have so many great Walleye fisheries that usually you can find what you are looking for within a reasonable drive.