Tottenham face a top-four battle after their title challenge collapsed with a 2-1 defeat at Burnley last month - but what's behind the abrupt decline?

Spurs had maintained form without the injured Harry Kane and Dele Alli, but the striker's return was followed by defeat at Burnley, a 2-0 loss at Chelsea and a 1-1 draw with Arsenal, while Alli's return ended in a 2-1 defeat at Southampton.

Spurs have crashed out of the title race since losing 2-1 at Burnley last month

Progression into the Champions League quarter-finals has mitigated the dip in league form, but Spurs have suffered a slight hangover after the busy January schedule.

It's just crazy. Three weeks ago we were 10 clear of Arsenal and it's just funny how a week in football can seem like it lasts forever. Danny Rose

The graphic below shows how Spurs played eight games in all competitions in January and have suffered a month-by-month, incremental decline in league form since.

Spurs' league results have declined since last month

Three months ago, Spurs lost to Wolves and Manchester United within a fortnight - but they picked up form in mid-January with four successive wins, before suffering the shock defeat at Turf Moor.

Spurs' rolling five-game average for goals scored and conceded suggests they peaked with a 6-2 win over Everton in December and have declined steadily since - currently conceding more than they are scoring for the first time this term.

Over a five-game average, Spurs are currently conceding more goals than they're scoring

The same rolling average for expected goals, which measures the true quality of chances, reveals poor results have not been from bad luck: opposing teams have clearly created a superior number of goalscoring chances in recent weeks.

Expected goals (xG) data, which measures the true quality of chances in front of goal, suggests Spurs have declined at both ends of the pitch in recent weeks

In terms of attack, a raft of stats remain unchanged since the Burnley game - except for a severe dip in the number of shots on target and, consequently, goals.

In fact, Spurs have attempted more dribbles and crosses since February 23, in addition to having more touches in the opposition box and creating slightly more chances - although xG reveals those chances have been of a lower quality.

In terms of attack, there has been a stark decrease in goals and shots on target since beating Leicester last month

On average, one in three shots on target is scored, but Spurs failed to hit the target for the first time this season during the 2-0 defeat at Stamford Bridge - and only managed three against Arsenal the following week.

Spurs failed to striker one shot on target for the first time this season against Chelsea

In terms of passing and defensive actions, very little has changed. Spurs have made slightly fewer interceptions and passes during their the past four top-flight fixtures, but have been marginally busier defensively.

Not much has changed in general play, except for taking slightly fewer passes and making fewer interceptions

In addition to a notable drop in shots on target, Pochettino's side have made three errors leading to goals over the past month - having made only two costly errors in their first 26 games this season.

Unsurprisingly, those mistakes have contributed to a spike in goals conceded - despite Hugo Lloris making far fewer saves over the past four games.

Three errors leading to goals in just four league games has led to a drastic rise in the number of goals conceded

The graphic below shows which players have been used most, before and since the defeat at Burnley - with each column scaled independently to clearly show which players have been used most during the periods.

The standout absentees of late have been Kieran Trippier, Ben Davies, Eric Dier, Harry Winks, Lucas Moura and Alli, while players that have been used more frequently include Danny Rose and Kyle Walker-Peters.

Both centre-backs Toby Alderweireld and Jan Vertonghen have missed one of the past four games, while the absence of Tripper and Dier may have also contributed to cracks emerging in defence.

On the pitch, there have been notable dips of activity in Spurs' own box, central midfield and down the flanks in advanced areas - which points towards deficiencies caused by the absentees.

Spurs have recorded less activity in central midfield and in advanced areas down the flanks

Pochettino has favoured a 4-1-2-1-2 or 4-2-3-1 formation this season, but started in a 3-5-2 for only the second time during the defeat at Burnley and used a 3-4-1-2 for the first time this campaign against Arsenal one week later.

After fruitless returns from experimenting with three-at-the-back systems, the Argentine returned to his 4-1-2-1-2 diamond shape last time out - the 2-1 defeat at Southampton.

Pochettino has been experimenting with three-at-the-back formations recently

The highest number of line-up changes occurred during the frantic festive period with five alterations in three successive games, beating Southampton, Burnley and Leicester - easing off with four changes in each of the following three games.

But injuries and European commitments have ramped up the number of changes again in recent weeks, with Pohettino shuffling at least three members of his starting XI in each of the last eight league games.

Spurs have been forced into injury-induced changes recently

In terms of physical exertion and potential fatigue, Spurs covered a season-high 124km against City in October and maintained that level with 123km against Wolves four days later.

But Tottenham recorded a season-low 108km during the defeat at Burnley last month and an unimpressive 115km against 'big six' opponents Chelsea - registering a new season-low of 107km at Southampton this month.

Spurs also recorded seasonal dips for sprints against Burnley and Chelsea in recent weeks

Again, Spurs recorded seasonal lows for sprints against Burnley and Chelsea before picking up to a season-average 115 against Arsenal - still 37 fewer than they achieved against the Gunners during the 4-2 defeat in December.

Spurs have covered season-low distances against Burnley and Southampton over the past month - having sustained far higher levels during the middle-third of the season

Conclusion

Spurs must rekindle the form that saw them challenging for the title only one month ago, if they are to finish in the top four.

The stats suggest this could be achieved from firing more shots on target and tightening up at the back, where recent errors have proved costly.

In addition, Spurs need to increase activity in central midfield and in advanced areas down the flanks, while fit-again Kane and Alli need to be at their best for the remainder of this season.

The London club also appear to have suffered from fixture congestion in December and January and struggled to manage Champions League exertions - recording season-low distances and sprints over the past month.

Harry Kane celebrates Tottenham's goal against Borussia Dortmund

Tottenham need to replenish freshness and restore stability after experimenting with numerous formations and line-up changes - although 16 members of their squad are returning from international duty this week.

Spurs are also set to move into their new stadium after their trip to Merseyside, hosting Crystal Palace on April 3 - before Manchester City visit one week later in the Champions League quarter-finals.

Does moving stadium affect results?

Pochettino will be hoping his side settle into their new home more seamlessly than their difficult transition to Wembley at the start of 2017/18 - which produced a considerable slump in home form.

Spurs struggled to settle at Wembley when they moved into the stadium temporarily for the start of 2017/18

So Spurs have it all to prove at Anfield on Sunday when they attempt to dent Liverpool's title tilt and boost their chances of securing another season among Europe's elite.

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