Let me give this a shot. All salmon species can have jacks. Pinks are the only one's who almost never have jacks, but chum and sockeye are not far behind them them in infrequency. Pinks are the most specialized (ie: highly evolved) of the Onchorhynchus genus, cutthroat are the least. In order, from least to most, cutts, steelhead, chinook, coho, sockeye, chum, and pink (these are just the one's you see around here, there are some more worldwide). Or approximately that way, I don't have the reference material in front of me. Anyway, as a species specializes it develops fewer trajectories. Pinks are so specialized they have developed only one trajectory, and even gone beyond the others to develop two year cycles. They also spawn only once, as do the other Onchorhyncus that we call salmon, another specilization. Cutts on the other hand can spawn multiple times, don't have to each year, can migrate long distances or not at all - basically they try everything. You don't even think of a cutthroat jack but they try that too. Steelhead do much the same things - resident rainbows are steelhead with stay-at-home tendencies, but their genes are the same as steelhead and their offspring may be anadromous as well as resident. And steelhead can stay in the ocean 1 to 3 years, maybe more, like chinook, and have jack trajectories like chinook. Chinook have dropped off the residualization trajectory, however, although they have the long ocean residence trajectory, even longer than steelhead. Steelhead also have either one or two year freshwater residence, and as do coho but less frequently. Chinook have both 0 and 1 year freshwater residence, but a year longer ocean residence, on balance similar in age to steelhead. All these also produce jacks, so that generations can crossbreed. But once you get into sockeye more trajectories fall off - they pretty much always reside in a lake for 1 year, occasionally 2, and yes, because of that there may be a jack look alike, but it will be a 2 lake fish that hits the salt one summer and returns. Chum never do this, instead migrating instantly to the ocean upon emergence and stay in the ocean 3-4 years, except the odd sport that comes back as a two year old jack (yep, seen scales off of one of these). Now the pink has developed so far as to have major cycles odd years, minor cycles even years. So they are all two year olds. However, very occasionally the two years will cross over - sometimes a pink stays out 3 years and sometimes comes back after one. This is so nobody gets completely inbred. The one salt pink happens pretty rarely, however, and the odds of seeing one of these in your angling career are slim to none.

Disclaimer: Some of this is theory based on a bunch of other theories loosely based on science