The revealing data that backs Paul Simpson's call for a Carlisle United transfer overhaul

Paul Simpson may have achieved his initial aim of keeping Carlisle United in the EFL, but he's been clear from the outset - that can only be the beginning.

While there have been some real highs under the returning manager, Saturday's bruising defeat to Harrogate Town was a real low.

And it served as a stark reminder of the change that needs to come over the summer; that overhaul that Simpson has long talked about.

Of course, the change that is required at Brunton Park isn't just confined to those taking to the pitch each week - but in the short-term, those are the easiest changes to make.

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Simpson admitted that the defeat in North Yorkshire has caused him to re-think some of the decisions that will be made over players in coming weeks, as continues to talk of a future where the Cumbrians achieve more than simply survival.

But just how far are Carlisle United under Simpson from being serious contenders in League Two?

We took a look at the data, courtesy of WyScout s.P.a, to find out:

Defensive data points to an over-reliance on one man

Carlisle have improved their defensive performances considerably since Simpson's arrival, having looked capable of shipping any number of goals earlier in the year.

But there will no doubt still be some concern at the number of chances being afforded to opposition teams - and this is one major area that will need to be fixed if Carlisle are to become contenders.

The graph above shows the xG of Carlisle's opponents since Simpson took charge - essentially, how many goals they have been expected to net against the Cumbrians.

Just twice has that number been below one, with the games against Barrow and Leyton Orient the only times the data has suggested the side shouldn't have conceded on at least one occasion.

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Carlisle's average xGA over this period has been 1.52 goals per game, significantly higher than the league best 0.88 of Forest Green Rovers.

And while this is a piece of data that some challenge, even a metric as simple as shots against shows the work Carlisle need to do defensively if they are to push on.

Carlisle are allowing the opposition an average of over 13 shots per game - although that is fluctuating heavily from fixture-to-fixture.

Simpson has spoken of inconsistencies in his team's performances in recent weeks, and this is a key one.

While the Blues have at times allowed their rivals as few as seven shots in 90 minutes, other games have seen them surrender up to 21 efforts on goal.

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That needs to be reduced and stabilised if the side are to climb the table.

Both these pieces of data point to something that has been fairly apparent at various points in the campaign: Carlisle have, at times, been over-reliant on the strong performances of Mark Howard.

While the experienced stopper has been in fine form throughout the campaign, moving forward the Cumbrians will need to ensure their results aren't too contingent on the man between the stick.

Inconsistencies in attack

And Carlisle are equally as inconsistent in their performance levels at the other end of the field.

As noted recently, the side haven't scored more than three times in a league fixture this season - and their chance creation is erratic.

Since Simpson's arrival, Carlisle have seen their xG (expected goals) per game range from between 0.77 and 2.18, in stark contrast to teams at the top end of the table, who average an xG over 1.5 per game.

That naturally suggests that the Blues need to ensure they fashion more meaningful chances on a more consistent basis if they are to progress up the table next term.

Of course, every team will have peaks and troughs during a season - but the wildly ranging figure show above underline the changing performance levels that Simpson has alluded to.

Control in possession could be key

Carlisle's manager has previously spoken of a desire to see his team exercise more control when in possession.

Of course, the last few weeks have been about simply winning matches and accumulating points to ensure survival. The quality of football has arguably been secondary.

But the data below shows that if Carlisle are to really push on, then they will require players who can retain possession well.

Carlisle's passing accuracy under Simpson is narrowly over 69 per cent - tracking well below the league average of 75.35 per cent and Swindon Town's league-best of 83 per cent.

Interestingly, some of Carlisle's better performances when it comes to keeping possession have been when the side has ultimately tasted defeat (Rochdale and Walsall away, for example).

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These are just three indicative measures, but it underlines the major changes that will be required to make the Cumbrians a force in League Two.

Simpson is well-aware of that and, once his future is determined, the transformation will no doubt soon begin - in whatever guise that takes.