Three head-scratching coaching decisions that could backfire

DeBoer's tenure in Dallas seems to have gone wrong due to his player management. After pulling starting goalie Jake Oettinger in the first period of Game 5 against the Edmonton Oilers, he threw Oettinger under the bus for the 6-3 loss. DeBoer explained in a news conference that he took the goalie out for being at fault in previous losses to the Oilers. DeBoer blamed the status quo at goalie for not advancing to the Stanley Cup Final instead of his choices as head coach.

According to Sportsnet NHL writer Michael Amato, DeBoer made the conference finals in six of the past seven seasons, but he's also been fired three times in that same stretch. Safe to say DeBoer's approach to keeping the locker room on his side could use improvement, but winning usually cures all. The Stars may see more demanding situations ahead if their next head coach doesn't deliver consistent success like DeBoer did.

Tottenham Hotspur sack manager Ange Postecoglou

After a 17-year trophy drought for the North London club, Postecoglou led the Spurs to a 1-0 victory over Manchester United in the UEFA Europa League final. Winning the second-biggest trophy in European soccer still wasn't enough to save his job. 

In fairness, Postecoglou oversaw a historically bad season for Tottenham in the Premier League. The Spurs finished 17th in the league with an 11-5-22 record and were 13 points shy of the relegation zone. 

Now, though, the team won't have the chance to build on its momentum with Postecoglou when it re-enters the Champions League next season. It will get a new manager whom it will have to adjust to after two seasons of trying to embrace Postecoglou's attacking mindset. 

Who knows how much time ownership will give this new manager to produce results, since Postecoglou only got two seasons and a trophy wasn't enough?

New York Knicks part ways with head coach Tom Thibodeau 

It took 25 years for the Knicks to return to the NBA Eastern Conference Finals, and it took one Finals loss to end Thibodeau's five-year tenure as head coach. As head coach in New York, Thibodeau went 226-174, building the Knicks back into a perennial playoff contender.

The Knicks were set to be competitive again next season, but ownership apparently believed the team had hit its ceiling under Thibodeau. However, teams that have fired Thibodeau after he led them to the playoffs have struggled afterwards. The Chicago Bulls have won three playoff games in the decade since they fired Thibodeau. 

Perhaps the Knicks won't repeat history and waste point guard Jalen Brunson's best years.