Why can't Sheffield United win a play-off final?

What have Sheffield United got to do to win promotion via the play-offs?

The 2-1 loss to Sunderland at Wembley is the 10th time the Blades have failed to go up via the play-offs and their fifth defeat in a final.

When Sunderland captain Luke O'Nien dislocated his shoulder inside the opening 120 seconds and Tyrese Campbell coolly clipped over Black Cats keeper Anthony Patterson 23 minutes later, the Blades must have thought their fortunes were finally turning.

And then.

Pretty much everything that could go wrong for Chris Wilder's side in north-west London did so. The footballing gods conspired against them once again.

Harrison Burrows arrowed the Blades into a two-goal lead 10 minutes before the interval, only for the video assistant referee (VAR) to intervene for the one and only time in the Championship this season to chalk the goal off for offside against Vinicius Souza who was blocking Patterson's line of sight.

Substitute Andre Brooks pickpocketed Dennis Cirkin and had the chance to double United's lead somewhat against the run of play in the second half with 20 minutes remaining, only to be denied by the studs on the end of Patterson's left boot.

It would perhaps prove to be the turning point and catalyst for a succession of events that slowly but surely saw this play-off final slip away from the Blades.

Championship player of the year Gustavo Hamer, who brilliantly set up the opener, was forced off with an ankle injury to be replaced by Ben Brereton Diaz, who himself limped off in the final minute.

Eliezer Mayenda scored Sunderland's equaliser and with extra time looming, Anel Ahmedhodzic clashed heads with his own team-mate Tom Cannon, suffering an injury and United's third of the game which meant he could not continue.

Sheffield United were down to 10 men for the closing stages and before they'd had a chance to make their sixth change, courtesy of the concussion sub protocol, Brighton-bound Tommy Watson - whose name wasn't even on the matchday programme - curled into the bottom corner to seal victory for Sunderland.

Wilder could be forgiven for bemoaning his side's bad luck in the final, this season in general and United's never-ending play-off curse, but he says they should have still seen the job through.

"It's not luck, it was in our hands," he said in his post-match news conference.

"The game was in our hands and we never felt in danger. Michael [Cooper] has not had a save to make.

"From a stats point of view, we were on top but we have to kill games off and have that quality. The opposition have taken their chances and punished us severely.

"We had an opportunity to change the narrative on the play-offs but we've not done that."

Debate about the decision by VAR to overturn Burrows' goal which would have made it 2-0 to United will likely rumble on well into the summer and Wilder says it gave Sunderland "a lifeline and energy".

"There will be a lot of talk about VAR," Wilder said. "We've played 46 games, two play-off games and all of a sudden it's a subjective decision.

"I don't think the goalkeeper [Patterson] saves it, I don't think he gets anywhere near it."

It was perhaps a season that was almost doomed before it had even started for Sheffield United after they were deducted two points for defaulted transfer payments.

Despite the early setback, the Blades still amassed 90 points.

However, they finished outside the two automatic promotion spots, behind sides who both hit the 100-point mark - something that has never happened before in Championship history.

Their points tally would have seen them promoted in 14 of the previous 20 seasons in the second tier and had they not been deducted two points, 92 would have been enough in 17 of those campaigns.

Meanwhile, only Leeds United (29) won more games than Sheffield United (28) in the regular season.

They may have finished 14 points ahead of Sunderland three weeks ago but the long grind of this season ultimately counted for nothing in the end.

"It's going to take quite a while to get over this and we're going to have to suffer and go through the pain again," Wilder said.

"The players will be hurting. We have to own it and suffer together. Most of all I'm disappointed for the supporters.

"Not to reward them with a win and the opportunity to play in the Premier League hurts a lot."

In many ways, today's heartbreak mirrored the regular season with 75% of it going to plan but ending in catastrophic fashion.

Three straight defeats by Oxford United, Millwall and Plymouth during the run-in saw United give up a five-point lead to fall to third, which was only further compounded when Burnley secured promotion with a 2-1 win over the Blades at Turf Moor on 21 April.

Wilder also said to lose in the manner they did with an injury-time goal in the final "really stings".

"They find a fabulous winner and it's chaos and pandemonium from their point of view," he added

"It's an incredibly bitter and disappointing situation we found ourselves in. The amount of games I've played and managed, it's not always been a fairytale."

But it has been very much a fairytale for Sunderland, who have been down to League One and back up again, and will return to the top flight for the first time in eight years.

On this occasion at Wembley, maybe it was the Black Cats who had all the luck.