Leeds United's defence was one of the key talking points over the international break.
Consecutive 4-1 defeats to Leicester City and Crystal Palace meant that Marcelo Bielsa spent the lay-off working hard to analyse just what was going wrong at the back for his side.
A 20-minute, 1,200-word answer to a question on what he had noticed from recent defensive performances in the pre-Arsenal press conference gave a clue into just how much work had gone in at Thorp Arch while the November internationals were being played and a clean sheet against the Gunners was further proof that few managers in world football work harder than Bielsa when it comes to analysing their team.
The Arsenal match was the first of a tough run of fixtures over the next month, with the likes of Everton, Chelsea and Manchester United all coming up before Christmas.
Bielsa will be hoping that the clean sheet against Arsenal will be the start of improved run at the back, but that thought is not shared by American forecasting website FiveThirtyEight.
The data experts run a constantly update Premier League prediction table using a sophisticated rating system that takes into account a range of factors to estimate a team's overall strength.
They have crunched the numbers after the latest round of Premier League fixtures and believe Leeds will finish the season 15th in the Premier League, one spot lower than they currently occupy.
Interestingly, the data also gives away a few other clues as to how Leeds' season will pan out.
They are predicting a final points tally of 44 points for Leeds, which is 1.16 points per game - down slightly from their current rate of 1.22 points per game.
In addition to this, their model also predicts the end-of-season goal difference, with their current prediction running at a -14 goal difference for Bielsa's side. Leeds' goal difference currently sits at -3, so this is a sizeable drop which indicates a lack of faith at the back from their various algorithms.
But as Bielsa showed, he is an expert in dissecting and then solving problems, meaning Leeds fans can be confident that the numbers can be proved wrong in the coming weeks and months.
