Correction: An earlier version of this story incorrectly said that Manhattan and Brooklyn are separated by the Hudson River. This version has been corrected.

Paul Pierce — acquired in a trade with the Celtics last summer — is part of the highest payroll in NBA history with the 9-18 Brookly Nets. (Maddie Meyer/Getty Images)

Separated by the East River and a 25-minute subway ride, the New York Knicks and Brooklyn Nets are connected by their collective misery, wasted millions and unfulfilled promise in a city that doesn’t take kindly to mediocrity. They have wealthy, eccentric owners who share a mutual belief — at least in practice — that future assets should be used for short-term investments, that big names and past reputations are more valuable than actual production and that problems are solved by tossing more money at them.

During a season in which they were supposed to be wrestling for the affections of New York basketball fans and jockeying for playoff positioning, the Knicks and Nets have been majestic palaces of ineptitude from star-studded but injury-riddled rosters.

A combined $190 million in payrolls — and another roughly $115 million in luxury tax payments — has resulted in 18 combined wins for the NBA’s two most expensive teams, who host the first two games of the NBA’s Christmas Day quintuple-header.

Carmelo Anthony recently referred to the Knicks as a “laughingstock” and Paul Pierce, the longtime Boston Celtic turned Net last summer, called his new team “bottom feeders.”

But despite the nonstop drama and embarrassing, bewildering moments from both organizations, the Knicks and Nets — both 9-18 — are only one game behind in the loss column for the eighth spot in the Eastern Conference and just 2½ games behind first-place Toronto in the Atlantic Division.

The Post Sports Live crew recalls the highlights from the year in Washington sports. (Jayne Orenstein/PostSportsLive/The Washington Post)

“We in a hole. Nothing we can do about that but keep climbing, keep fighting,” Anthony said recently. “No need for us to think anything else than to try to get out of this hole we in now. We got to do it. We got to do it.”

Anthony might not even be available when the Knicks host Kevin Durant and the Oklahoma City Thunder after suffering a sprained ankle on Monday in Orlando. But the Knicks have been fighting through injuries and poor chemistry all season while coming off one of the more successful runs for the franchise in nearly 19 years — one in which it won 54 games and a division title and advanced to the second round for the first time since 2000.

In the offseason, the Knicks traded for Andrea Bargnani, fired General Manager Glen Grunwald and replaced him with Steve Mills in moves that harkened back to the dysfunctional days of the recent past under owner James Dolan. This season, the Knicks have dealt with J.R. Smith’s erratic shooting, injuries to center Tyson Chandler and point guard Raymond Felton and an over-reliance on Anthony to bail them out with his scoring.

“It’s been a struggle to try to get chemistry with our ball club,” Knicks Coach Mike Woodson said this week. “I’m not sitting here complaining. We’ve just got to figure it out on the fly.”

Speculation about Woodson’s future has been a topic of discussion all season, and the temperature on his apparent hot seat increased last week after a loss to the Washington Wizards in which the team surrendered a go-ahead layup by Bradley Beal with 6.9 seconds left but failed to call a timeout — despite having three at their disposal.

Instead, the Knicks settled for an off-balance, one-legged runner by Anthony that hit all backboard. Woodson accepted the blame, explaining he didn’t have time to react.

When asked afterward about Woodson’s job security, Anthony said, “There’s nothing to discuss. He’s our coach, and we’re rolling with him.”

For all of the frustration with the Knicks, their early struggles pale in comparison to the Nets, who have an overpriced roster that is long in the tooth and short on athleticism and experience on the bench. And the injuries have been piling up.

The latest was the loss of all-star center Brook Lopez — the team’s youngest starter and most efficient offensive player — for the rest of the season with a broken right foot; it’s the same foot he has injured three times since 2011.

Lopez’s absence comes just as the team had welcomed back point guard Deron Williams from an ankle injury, and his absence diminishes an already lackluster matchup against the Chicago Bulls. Chicago will be without former league MVP Derrick Rose, who came back from an 18-month layoff because of a left knee injury only to suffer a right knee injury that likely will sideline him the remainder of the season.

When Russian billionaire Mikhail Prokhorov purchased the Nets in 2010, he said his goal was to win a championship in five years — but the team has since preferred the quick fix to the slow build. After finally ending a five-year playoff drought last season, the Nets acquired aging, past-their-prime veterans Kevin Garnett and Paul Pierce to make a serious run for a title.

But Pierce and Garnett have had a difficult adjustment from Kelly green to black.

“We’re both trying to figure out how we can make this team better on both ends and not just come in and be a voice,” Garnett said, “but obviously putting a physical presence to the game and coming in and doing it.”

Brooklyn also decided to place the most expensive team in NBA history in the hands of the seemingly overmatched Coach Jason Kidd, a key piece with the Knicks last season before retiring after a 19-year career. The campaign started with Kidd missing the first two games while serving a suspension for driving while ability impaired. Since then, he has been fined $50,000 for having Tyshawn Taylor intentionally walk into him so he could spill a soda, delay the game and draw up a play after the team had run out of timeouts. Kidd also demoted former top assistant Lawrence Frank — his former coach with the New Jersey Nets — after the two clashed over “different philosophies.”

Following Monday’s loss to the Indiana Pacers, Kidd told reporters his team is “kind of getting comfortable with losing. And we got to make a stand with that.”

If neither team can turn it around, the futures for the Knicks and Nets aren’t promising, either. Anthony will be a free agent next summer, though the Knicks can offer him an extra year and almost $30 million more than any other suitor. The Knicks’ first-round pick in a talent-rich 2014 draft belongs to Denver as part of the Anthony deal.

The Nets are committed to $64 million in salaries for the 2015-16 season, and their first-round picks have either been traded away or could be swapped with no protection for the next five years. Pierce will be gone as a free agent next summer, and Garnett could retire, which could make the decision to surrender three first-round picks to the Celtics even more disastrous.

Time and a weak Eastern Conference are still on their sides.