The difference between two of Seattle’s professional sports franchises can be summed up in 10 words.

The Seahawks generally know what they’re doing. The Mariners don’t.

The Sounders, incidentally, also seem to know what they’re doing, but including them would break the 10-word limit.

There are, of course, exceptions to this characterization. Almost by the law of averages, the Mariners have made a few good transactions in their history. The Seahawks have taken the wrong step in personnel decisions a few times.

Two of those decisions, made during the 2016-17 offseason, probably kept the Hawks out of the National Football League playoffs this season for the first time since 2011.

One was based on a faulty team-building concept. The other, strangely, may have been a case of club executives buying into a players’ mentality.

In reading books and magazine articles authored by past and present professional football players, one thing that mildly surprises me is the disdain directed toward kicking specialists. To many position players, punters and placekickers are necessary evils — non-athletic geeks who really don’t belong in the NFL fraternity.

In the entertaining and surprisingly enlightening 2008 book “Then Zorn Said to Largent…,” co-authors Dave Wyman and Paul Moyer (ex-Seahawks-turned-radio commentators) refused to even select a punter for their all-time Seahawk teams. They dismissed the position with the identical phrase, “Who cares?” Moyer went a step further by adding, “We could put the best ballboy in this category.”

They took a similar attitude toward placekickers. Moyer didn’t select one of those, either. Wyman chose Josh Brown (later to become infamous over domestic violence allegations), apparently on the basis that he occasionally made tackles on kickoffs.

Current Seattle general manager John Schneider is a pretty sharp guy. Even when he was forming the 2017 roster, he likely knew that former Minnesota Viking Blair Walsh wasn’t the equal of longtime Seahawk placekicker Steven Hauschka.

But Hauschka, coming off an erratic 2016 campaign, was still going to command a higher salary than Walsh — money that the Hawks could spend on position players. Factoring salary-cap considerations into the equation, Schneider probably reasoned that the difference between the two kickers would be so slight that few people would care.

In truth, that looked like a good bet midway through the 2017 campaign. Walsh was having an excellent season until critical misses against the Washington Redskins on Week 10 sent his confidence — and the Seahawks’ campaign — into a downward spiral that left the Hawks one game shy of the playoffs.

Financial considerations also played a role in Schneider’s other questionable decision.

With much of their resources directed toward retaining their big-name talent, the Hawks seemingly adopted the strategy of assembling an offensive line on the cheap (relatively speaking) and have respected offensive line coach Tom Cable coach them up to respectability.

That philosophy has worked to a limited degree in the past, but not in the last couple of seasons. It’s the main reason the Seahawks have been unable to generate a consistent running game since the departure of Marshawn Lynch and why quarterback Russell Wilson is perpetually scrambling for survival. With a less mobile QB than Wilson, the Hawks would have been lucky to go 4-12 this past season.

Despite those shortcomings, I’m not buying the theory that the Hawks are destined for a prolonged decline.

For all the hand-wringing in Seattle, the Seahawks still had a 9-7 record —despite suffering major injuries that they had been fortunate to avoid in the past.

Schneider and the remainder of his management team don’t have to commit themselves to a total roster makeover. In the past, they’ve proven they can make the necessary tweaks that would allow them to return to playoff contention.

As for the Mariners, I once believed that general manager Jerry Dipoto knew what he was doing.

My faith was shaken, however, by his refusal to pull the trigger on trade deadline deals the past two years when the M’s were in contention for wild-card playoff berths.

Dipoto’s refusal to consider most free agent acquisitions has also proven to be a problem. In theory, his contention that long-term free agent contracts are counter-productive makes some sense. The Mariners have been burned by plenty of those (remember Chone Figgins?) in the past.

In practice, however, most world championship teams contain at least a few free agents.

After striking out in the sweepstakes to obtain much-touted Japanese pitcher-designated hitter Shohei Ohtani, Dipoto suddenly reversed course and proclaimed himself satisfied with Seattle’s starting pitching. Expecting a rotation consisting of oft-injured James Paxton, past-his-prime Felix Hernandez and an assortment of journeymen to match up favorably against the Houston Astros is delusional.

In other words, the aging Seahawks are still a better bet to make the playoffs next season than the Mariners.