Peterborough United: A statistical look at recent failures to return to the Championship. Part One: 2015-16 season.

Data is only readily available for the last five seasons so we will cover a season a day from Monday to Friday starting today (September 7) with the 2015-16 campaign.

Key: Expected Goals (xG): A model which measures the likelihood of any individual shot being scored, with 1 being a 100% chance of scoring and 0 being a 0% chance of scoring. It takes into account factors such as angle, distance and body part of the shot taken.

Expected goals against (xGA): As above but for shots conceded.

Expected Points (xP): The number of points a side would have collected if the side who had the better chances to score had won, based on each team’s xG data.

Per 90 (p90): How often a team or player performs a certain action every 90 minutes of game time.

Key Pass: A pass or cross which creates a clear situation or opportunity for a goal but the receiving player misses this chance.

Deep Completion: A successful pass (not cross) that finishes within 20m of the opposition goal.

2015-16 Goals galore (at both ends) and a bottom half finish.

Managers: The 2015/16 season is dominated by memories of two managers, who contrasted in style but ultimately both failed to live up to expectations. Posh started the season with the pragmatic, but out of his depth, Dave Robertson. He was an excellent youth coach who had been well regarded in his previous role as Academy Manager, but struggled to find his feet at senior level. His permanent replacement, Graham Westley, then seemed to use his short spell at London Road to try to prove he was the Football League’s answer to Pep Guardiola as opposed to the ‘English dinosaur’ he had previously been portrayed as. However, Westley talked a far better game than he was ever able to bring to life on the pitch.

Dave Robertson had taken over towards the back end of the 2014/15 season, but was dismissed six games into the new campaign having collected just one win and four points. A key issue for Robertson’s Posh side was their impotent attack, which seriously lacked purpose and structure and therefore struggled to carve out decent openings.

Posh actually took an impressive number of shots under Robertson, at 16.67 shots per game, which was more than any side managed over the course of the League One season. However, these shots were largely taken from terrible positions. Posh’s xG per shot was 0.061 under Robertson, which means we would only expect them to score from 6.1% of their shots. The league average was 0.100, with Walsall having the lowest in League One over the whole season of 0.082. Posh only hit the target with just 21.06% of their shots, a further sign that they were shooting from terrible positions, as even League One’s least accurate shooters Chesterfield did better, hitting the target with 30.00% of their shots.

Typically, sides who are ineffective going forward try to make-up for these inefficiencies by being extra stingy at the back. Yet defensively Robertson’s Posh were playing like a team that was battling relegation rather than one set to challenge near the top of the table. Posh conceded 1.83 goals per game, with only relegated Colchester United conceding goals at a quicker per game rate. Posh’s expected goals against (xGA) per game of 1.52 was also worse than all bar three sides managed over the course of the season.

Stylistically, Posh played a traditional 4-4-2. The passing was direct, with 20.98% of Posh’s passes being hit long and at an average of just 2.48 passes per possession. Only two sides in the league had a lower pass accuracy than Posh’s 72.07%, and they were the ultra-direct Millwall and Gillingham. However, unlike those two sides, Posh lacked a natural target man to build attacks around in the final third, a clear sign of Robertson’s muddled and uninspiring tactical thinking.

Where it is probably fair to criticise Robertson for lacking confidence to manage at first team level, the same cannot be said of his permanent replacement Graham Westley. Upon his appointment, Westley took the bizarre step of writing an open letter to the fans with his objectives as Posh manager; 600 passes and 25+ shots per game. Both objectives turned out to be wildly ambitious.

Firstly, having a stated passes per match target is pretty pointless. In most situations, the primary purpose of a pass should be to increase the chance of successfully moving the ball towards the goal and/or scoring a goal. In general, passing for the sake of passing is tedious to watch as a fan and does not do much to enhance that sides chances of winning, especially as it allows the opposition defence to get organised and become harder to break down. As for 25+ shots, well let’s just say that Manchester City’s record breaking 2017/18 side managed 16.97 shots per match in their Premier League matches, so you can make your own mind up as to how realistic that target was!

In his defence however, while he fell short of his own ludicrous targets, he did succeed in implementing a drastically different style of play and greatly improved Posh as an attacking unit. Posh’s passes per match also jumped from 313.83 to 378.69, with an increased pass accuracy of 79.65%. Furthermore, Posh took an average of 17.03 shots per game almost two more than Coventry City who took the second most shots in the league. Importantly, unlike under Robertson, Posh weren’t just shooting from anywhere and created a number of good openings. Their xG per match of 1.65 ranked them top of the pile in League One, while a goals per game rate of 1.69 was bettered by only three sides. His gung-ho approach also made for some fairly entertaining matches for fans of high scoring games as Posh games under Westley averaged a hefty 3.25 goals.

Whilst Westley was pursuing his lofty attacking goals and transforming Posh into an impressive attacking unit, he appeared to completely forego the defensive side of the game. Perhaps he was so desperate to dispel the negative football narrative that followed him to Posh he forgot that keeping the ball out of your own net is a pretty helpful skill when trying to win football matches. They conceded 1.56 goals per game, the joint fifth most in the league. Their xGA was even higher at 1.68, with only bottom placed Crewe Alexandra having a worse record. Only three sides conceded more shots that Posh’s 15.61 a game. For a manager who thought it was appropriate to play Marcus Maddison on the left of a back four maybe this is hardly surprising.

Overall, the 2015/16 season was a statistical anomaly. Posh scored the joint most goals in the league but had the joint fourth worst defensive record. The high scoring nature of the matches meant Posh only registered six draws, the joint lowest total of any League One side in the past five years. However, in both this season and the seasons to come it becomes apparent that Posh are not your typical League One side and regularly throw up interesting statistics. Eventually Posh finished 13th, their only bottom half League One finish in the MacAnthony era, on their second lowest League One points total of the same era (63).

After both Robertson and Westley there were two-game spells under Posh legend Grant McCann, originally on a caretaker basis then permanently second time round. McCann was a revelation during his four games in charge, as Posh collected 10 points scoring 15 goals in the process. This ultimately saved them from a totally disastrous season and any further embarrassment. The question heading into 2016/17 was whether he could he come close to sustaining this over the course of a full season,