RUSSELL Martin's decision to alter Jack Stephens' role in defence has certainly been divisive among supporters.

The boss needed little prompt before launching a passionate defence of his decision after their 0-0 draw with Blackburn on Saturday.

For the first 32 games of the season, Southampton played a more traditional back four with two centre-backs and two full-backs.

Stephens was out for a large portion of this time, missing 17 Championship fixtures, having suffered an injury in August.

The skipper did step into right-back on two occasions but was tasked with playing in a similar mould to James Bree rather than his new role. 

Martin has changed the 30 year old's role to help play through the opposition’s press when building from the back.

READ MORE: Russell Martin launches defence of Jack Stephens' role

We first saw this used, to great effect, at West Brom, where Saints were comfortable 2-0 winners - apart from 15 minutes before half-time. 

By having Stephens invert, Southampton have an additional passing option, helping to negate the opposition's two-man press.

Daily Echo: Demonstration of how Southampton's defence and Flynn Downes set up during build-upDemonstration of how Southampton's defence and Flynn Downes set up during build-up (Image: SDE)

This takes some demand off Downes to play forward quickly under pressure in order to spark an attacking sequence. It is much harder to cut out the passing lane to both.

If a team is successful in doing that then it likely leaves another player free. Kyle Walker-Peters was often the target when Southampton could not play through the middle on Saturday at Blackburn.

As the image below demonstrates, Downes becomes the only passing option when Stephens does not invert, therefore making their build-up easier to stifle.

Daily Echo: Demonstration of Southampton's build-up earlier in the seasonDemonstration of Southampton's build-up earlier in the season (Image: SDE)

Downes insists he has enjoyed the tactical switch because he feels it has made his job easier when teams decide to mark him out of the game.

He told the Daily Echo: "With Stevo coming in there, we work around each other. If I see him go deep then I will go higher.

"It allows me to be a bit more attacking. It's another option for us to play out. To be fair, I'm loving it. I love it when he comes in.

"I can play off him. Before, it was hard when a team man-marked me. If I came for the ball there was no chance I could get it.

"Now, if he comes in and someone is man-marking me then the opposition player doesn't know what to do. It frees me up."

READ MORE: Flynn Downes responds to Southampton and West Ham future

Those sentiments were echoed by Taylor Harwood-Bellis, who agreed that playing out from the back becomes less challenging when Stephens is inverted.

"It helps us, we don't just do it because it looks good," the centre-back told the Daily Echo. "That is the way we can get out. In the game, the manager changes things to help us.

"It's all about getting numbers at the back to help us in the right spaces. It works every time. Jack is incredible at it. He is the best player we have to do it."

When it works, the positioning of Stephens can create space for others around him, as seen with Stuart Armstrong in the example blow.

Ipswich winger Kayden Jackson has positioned himself to cut out a potential pass to Stephens (circled), leaving S Armstrong free on the left.

Daily Echo: Jack Stephens movement creates space for Stuart Armstrong on the leftJack Stephens movement creates space for Stuart Armstrong on the left (Image: EFL)
After receiving the pass from Jan Bednarek, S Armstrong drives at Ipswich before threading a through ball which Adam Armstrong fires home.

Daily Echo: Adam Armstrong fires a first time finish after racing on to Stuart Armstrong's through ball.Adam Armstrong fires a first time finish after racing on to Stuart Armstrong's through ball. (Image: EFL)

This goal is more down to S Armstrong's drive and subsequent pass than the positioning of Stephens, but his role should not be overlooked.

The danger of this tweak comes when Southampton lose the ball further up the field. 

By asking Stephens to step inside, they lose defensive protection in the wide areas, even more so if the other full-back has pushed forward.

As the images below demonstrate, that leaves them susceptible to counterattacks. James Bree (out of frame) and David Brooks combine but lose the ball in the final third.

Daily Echo: Ipswich launch a counter after Saints lose the ball in their final thirdIpswich launch a counter after Saints lose the ball in their final third (Image: EFL)

Ali Al-Hamadi has options in space to both his left and right, but ultimately makes the wrong decision and tries to shoot, allowing Bednarek to snuff out the chance.

Daily Echo: Ali Al-Hamadi allows Saints to recover by not playing in a teammate out wideAli Al-Hamadi allows Saints to recover by not playing in a teammate out wide (Image: EFL)

Daily Echo: Jan Bednarek eventually wins back possession on the edge of the boxJan Bednarek eventually wins back possession on the edge of the box (Image: EFL)

Had the 22 year old made the most of his supporting players, Ipswich could have taken full advantage of the vacated space.

Blackburn also made the most of the space in wide areas at Ewood Park, often looking to switch play to run at the areas left by the full-back's movement.

Although it feels as though Southampton are now leaving themselves more at risk defensively, they have not faced more shots since making this tactical switch.

Across the entire season, they have conceded 11.1 shots on average per game, slightly more than the 10.1 shots faced per game since the alteration.

There has also been a slight decrease in the expected goals Saints have allowed, down to 0.83 from the season average of 1.03.

There has, however, been an increase in the goals conceded per match, which is by far the most important metric. Goals conceded is up slightly to 1.5 compared to 1.3 across the whole season.

Martin has put this down to being "rubbish" in both boxes and they have undoubtedly lost some of the steeliness they showed earlier in the campaign. 

Daily Echo:

In terms of creating chances, Southampton are registering the same number of chances as they did before changing the system, seeing a minimal increase in xG.

Small increases across a seven-game period can be inflated by a single game - they had 26 shots at Birmingham but only seven at Blackburn.

But what stands out the most is that Martin will not move away from this model until he feels it is no longer helping them.

On Saturday he concluded: "I don’t see it as a problem, nor is the formation or how we start the game.

"They have solutions for a lot of things. It’s our job to keep giving them solutions in the final third.

“We aren’t going to change but we will try to keep getting better and finding a solution for the problems we might face.

"If Jack stops working for us in there and the lads don’t get enough from it then we will look at the next bit."