Steve Cotterill is refusing to reveal the secrets of Pompey’s defensive success.
The Blues boss is staying coy on the reasons for the turnaround at the back for his men this season.
A new-found defensive resilience has been behind the team’s charge up the table.
Eight clean sheets have arrived in the past nine games, as seven wins were picked up.
The club’s post-war league record for minutes without conceding fell along the way, as Jamie Ashdown went 536 minutes without shipping a goal.
That is a monumental turnaround from earlier in the campaign, with Pompey keeping just three clean sheets before that run.
Cotterill is keeping quiet on what is behind the upturn in defensive fortunes, though.
He said: ‘We’re not letting out what we’re doing and what we’re doing right.
‘Then it will be out and become public knowledge and everyone will jump on the bandwagon.
‘We’ll be opening ourselves up if we do that. But if we can keep on progressing and showing the same dedication and organisation, we will be absolutely delighted.’
Cotterill reserved praise for the role keeper Ashdown has played in the improvement at the back.
His saves were key in his team’s most recent success at Leicester before the international break.
Ashdown has played every minute of every game so far since being made No1.
Cotterill said: ‘Jamie keeps making great saves. He’s another who has been first class.
‘I want to see him have 46 games next to his name come the end of the season.’