Was always told the first run were mostly Russian River reds that due to the river tend to run smaller so they can breed. The bigger fish and most of the second run are Kenai reds that spawn and rear in Kenai Lake, then also spend time in Skilak Lake before heading out. They are bigger when they leave the river to the salt water, and so get bigger in the ocean and have a better survival rate.
Otterman is also right. Most of the biggest fish are 5 year olds. Seems to be a big year for 5 year olds as well as my son just got back from SE and they were seeing much larger reds there than in the past. I am curious how they are looking in the bay, but haven't talked to my brother-in-law yet.
Could be this is a bad year for Kings returning, but could be a great year for reds.
Some people are like slinkies - not really good for anything, but they bring a smile to your face when pushed down the stairs.