Kenny Jackett has turned to an ‘evolved’ 4-4-2 formation in a bid to overcome Pompey’s stuttering start to their League One season.
The Blues boss has made a ‘subtle change’ to his favoured 4-2-3-1 system which he feels can get his strikers firing on all cylinders.
Last month’s lacklustre 1-0 loss at Wycombe prompted Jackett to tweak his tactics.
Brett Pitman is now partnering John Marquis up front rather than featuring in the number-10 position.
That approach was taken in the 4-0 south-coast derby defeat to Southampton, as well as the 1-0 victory over Bolton last weekend – a game that Pitman head home the winner.
Jackett insists he’s not ripped apart the formation he’s used for the vast majority of his time at Fratton Park.
But he feels the adjustments can help 19th-placed Pompey hit top form, after collecting just nine points from eight matches this term.
The manager said: ‘I think it has evolved that way coming off the back of the Wycombe game because the system and set-up just didn't work.
‘Against Southampton, we played 4-4-2 and then again on Saturday.
‘I understand there’s a very thin dividing line between 4-2-3-1 and 4-4-2. One is only an abbreviation of the other, I think.
‘Brett was perhaps coming too deep in games and needed to get up and closer to John.
‘From Southampton and then Bolton, our number-10, Pitman, was to get really close to Marquis.
‘Then if it evolves and turns into a front two, which it did in that game, then I’m quite happy to see how that develops now.
‘We also have Ellis Harrison and have three very strong forwards in that area.
‘The main thing is our team evolving because it was a poor set-up and performance at Wycombe.
‘Against Bolton, there were signs I hope of cohesion and creativity going forward.
‘You always ponder every set-up. Since I’ve been here, I’ve mainly gone 4-2-3-1 with a defined player operating more in midfield than up front.
‘It's maybe a subtle change and there’s no great difference really.
‘Fine-tune is a good way (to describe it). It’s not ripping it apart necessarily, although you do see plenty of clubs and managers changing systems within a game.
‘It’s got to hit the ground running. There were some good signs against Southampton and we put a lot of effort into that game but lost 4-0.
‘There was a step in the right direction last Saturday and hopefully something we can build on.’
Jackett revealed his Pompey approach last season revolved around wing-wizards Jamal Lowe and Ronan Curtis, who netted 17 and 12 goals respectively.
But after bringing in strikers Marquis and Harrison in the summer, coupled with the departure of Lowe to Wigan, the manager believes the Blues will have more success if his wide men’s primary focus is to provide assists.
Jackett added: ‘Last season's team was set up for the wide men to do well. They delivered and did well.
‘It’s quite unusual, though, when your wide men score more goals than your forwards, but it evolved that way.
‘Jamal was our top scorer and Ronan had a good goals total as well.
‘This season, it’s been slightly different and maybe a bit more traditional because I do feel there are goals in Marquis, Pitman and Harrison during the course of the season.
‘The wingers may just be more providers, which is traditionally their role.
‘Marcus Harness can do a bit of both, although he’s our best crosser of the ball.’