SYDNEY Swans coach John Longmire was at a loss to explain his team's erratic performance in its 28-point loss to St Kilda at Etihad Stadium.

The Swans doubled the Saints' scoring shots in the opening quarter and tripled the Saints' scoring shots in the last quarter.

But Longmire was unable to put his finger on why his team dropped off so badly during the second and third quarters.

"It's hard to do immediately after the game," Longmire said.

"We were winning the ball and having scoring shots in the first quarter.

"And then it was a complete turnaround."
 
The Saints kicked 11 goals to four during the middle quarters and led by 50 points when Ahmed Saad kicked a goal at the 26-minute mark of the third term.

"We started well," Longmire said. "We had eight shots to four at quarter-time.

"And then St Kilda really got going. They won the contested ball in the second and third quarter.

"We just started to fumble. It affected our ball use.

"We just went backwards in the second and third quarters."

Longmire said his team's lack of consistency is a concern.

The Swans' efforts have wavered from quarter to quarter during losses to Adelaide, Richmond and St Kilda over the past month.

They put up a consistent effort during their 101-point drubbing of Melbourne last week but that has proven the exception.

"St Kilda played a really good game," Longmire said.

"Their pressure was outstanding for the whole game; their consistency didn’t waver.

"Our pressure really wavered.

"That affects your cleanness at ground level, it affects your ball use, it affects everything if you haven't got that hardness."

Swans midfielder Kieren Jack described his team's second quarter, in which it failed to score from the seven-minute mark, as "jittery".

"We fumbled the ball," Jack said.

"That's not good enough from us.

"Their midfield lifted. Hayes got going. We couldn't stop their momentum.

"That was probably the most disappointing thing, our midfield against theirs.

"They got on top and we couldn't hold them out."