A blistering start to life in England saw Diego Costa hit seven goals in his opening four appearances for Chelsea back in August, making himself and his new club the early favourites for Premier League honours.

Fast forward 26 games and Chelsea are cantering towards the title and Costa is still the division's most prolific scorer with 19 goals, although it is a spot he shares that spot with Tottenham's Harry Kane, a player who did not score his first Premier League goal until November 2.

Costa's latest hamstring injury puts Kane firmly in the driving seat to finish the Premier League's top scorer in his first season as a bona fide starter, but a more detailed look into the division's strike force reveals an alternative candidate with a claim to being labelled the most deadly.

Of players to have netted five or more goals this season, no one has found the back of the net more frequently than Arsenal's Olivier Giroud. The Gunners' frontman, who missed the best part of three months earlier in the season due to injury, boasts a return of 0.87 goals per 90 minutes, the highest in the Premier League.

Five things we learnt from Arsenal v Liverpool 5 show all Five things we learnt from Arsenal v Liverpool 1/5 You couldn’t blame Raheem Sterling for seeing his future elsewhere Amid all the talk of money-grabbing Liverpool’s star youngster was keen to point out that his priority was winning trophies. One can talk at length about whether there is anything wrong with maximising your earnings during a short career the more prescient question is: can he challenge for honours at Anfield?

On the basis of the last two displays by Brendan Rodgers’ side the simple answer is that Sterling is unlikely to have a bulging medal cabinet if he spends his career in the North West. Aside from the dangerous attack where the 20-year-old dovetails with Daniel Sturridge and Philippe Coutinho this side seemed short of quality in every position.

If his next destination is to be The Emirates then Arsenal fans must be salivating. Playing in his preferred role through the middle Sterling looked like the only man capable of breaching the Gunners’ defence, coming close to giving Liverpool the lead on a rapid counter in the first half before winning the penalty that gave the visitors a slither of hope. Getty 2/5 Who said Mesut Ozil and Alexis Sanchez can’t play together? Arsene Wenger has always believed that, given time, good players will learn to play together. This afternoon his faith in his two most expensive signings was reaffirmed, as the pair combined menacingly for the 70 minutes that they shared the pitch. Along with Aaron Ramsey the three behind Olivier Giroud interchanged position, with the German in particular providing no real reference point for Liverpool’s defenders.

Ozil’s ability to find and create space for his colleagues gave Alexis Sanchez the opportunities to show that any perceived dip he has been playing through is more statistical than based on performances.

Considering their complimentary skill-set, Sanchez’s ability to drive at defenders and Ozil’s ability to find him, it seemed inevitable that the two would click sooner or later. The goals they both scored were just rewards for eye-catching performances. GETTY 3/5 Martin Skrtel may be Liverpool’s most important player For the first quarter of the match Kolo Toure seemed to think he was back with his old club, so disastrous was the Ivorian’s start. He gifted the ball to Ramsey early on and it took a fine save from Simon Mignolet to stop the Gunners grabbing an early lead.

Toure’s panic seemed to spread amongst his colleagues with Mamadou Sakho, who had gelled so well with Skrtel, reverting to type and putting in a disorganised and chaotic display. Therefore it was left to 21-year-old Emre Can, who has spent most of his career in midfield, to try to stem the tide. He was unable to as Arsenal’s vibrant attackers proved to Rodgers that their quality beats the quantity of Liverpool’s back three every time.

It says something for how much faith the Liverpool manager has lost in his £20 million signing that he preferred the ageing Toure ahead of Dejan Lovren. Without Skrtel Liverpool’s defensive resources are suddenly looking very threadbare. GETTY 4/5 Will Mathieu Debuchy get back into the Arsenal side? It seems a long time ago that young right-back Hector Bellerin was made to look very much the novice by Borussia Dortmund’s formidable attack in September’s Champions League tie.

Another outstanding performance from the 20-year-old was capped by a goal that his attacking colleagues would have been proud of, as he drove into the area before curling a shot into the far corner with his wrong foot. His combination with Ramsey on the right provided the Gunners with stability in defence and menace going forward. Giving away a penalty was unfortunate, but Bellerin won’t be the last player to be undone by the trickery of Sterling.

With Bellerin on one flank and Nacho Monreal on the other Arsenal’s defence also looks more balanced than it has since the days of Sol Campbell. The right-back’s pace allows him to cover for Per Mertesacker whilst Monreal’s experience playing in the middle has made him a more complete defender. With Francis Coquelin shielding Arsenal could well be on their way to more solid performances against top sides. Getty 5/5 Only one of these sides will be in contention for the title next season As delighted as Wenger will be to see his side pick up another commanding win over a rival he must be left wondering what might have been if Arsenal had only been able to find this purple patch at the start of the season.

With a transfer window ahead to address the few issues that remain in his squad, a world-class goalkeeper being the most pressing, the Gunners manager may soon be able to mount his first true title challenge in over a decade.

Their forthcoming game with Chelsea may come too late for them to catch the Blues but it represents a perfect opportunity to lay down a market for 2015/16. For Brendan Rodgers the picture was already unclear before Sterling cast his future at Anfield into doubt. Both his squad and his first 11 seem some way short of the quality to challenge for the Champions League, let alone to reignite memories of last season’s unlikely charge for the top. 1/5 You couldn’t blame Raheem Sterling for seeing his future elsewhere Amid all the talk of money-grabbing Liverpool’s star youngster was keen to point out that his priority was winning trophies. One can talk at length about whether there is anything wrong with maximising your earnings during a short career the more prescient question is: can he challenge for honours at Anfield?

On the basis of the last two displays by Brendan Rodgers’ side the simple answer is that Sterling is unlikely to have a bulging medal cabinet if he spends his career in the North West. Aside from the dangerous attack where the 20-year-old dovetails with Daniel Sturridge and Philippe Coutinho this side seemed short of quality in every position.

If his next destination is to be The Emirates then Arsenal fans must be salivating. Playing in his preferred role through the middle Sterling looked like the only man capable of breaching the Gunners’ defence, coming close to giving Liverpool the lead on a rapid counter in the first half before winning the penalty that gave the visitors a slither of hope. Getty 2/5 Who said Mesut Ozil and Alexis Sanchez can’t play together? Arsene Wenger has always believed that, given time, good players will learn to play together. This afternoon his faith in his two most expensive signings was reaffirmed, as the pair combined menacingly for the 70 minutes that they shared the pitch. Along with Aaron Ramsey the three behind Olivier Giroud interchanged position, with the German in particular providing no real reference point for Liverpool’s defenders.

Ozil’s ability to find and create space for his colleagues gave Alexis Sanchez the opportunities to show that any perceived dip he has been playing through is more statistical than based on performances.

Considering their complimentary skill-set, Sanchez’s ability to drive at defenders and Ozil’s ability to find him, it seemed inevitable that the two would click sooner or later. The goals they both scored were just rewards for eye-catching performances. GETTY 3/5 Martin Skrtel may be Liverpool’s most important player For the first quarter of the match Kolo Toure seemed to think he was back with his old club, so disastrous was the Ivorian’s start. He gifted the ball to Ramsey early on and it took a fine save from Simon Mignolet to stop the Gunners grabbing an early lead.

Toure’s panic seemed to spread amongst his colleagues with Mamadou Sakho, who had gelled so well with Skrtel, reverting to type and putting in a disorganised and chaotic display. Therefore it was left to 21-year-old Emre Can, who has spent most of his career in midfield, to try to stem the tide. He was unable to as Arsenal’s vibrant attackers proved to Rodgers that their quality beats the quantity of Liverpool’s back three every time.

It says something for how much faith the Liverpool manager has lost in his £20 million signing that he preferred the ageing Toure ahead of Dejan Lovren. Without Skrtel Liverpool’s defensive resources are suddenly looking very threadbare. GETTY 4/5 Will Mathieu Debuchy get back into the Arsenal side? It seems a long time ago that young right-back Hector Bellerin was made to look very much the novice by Borussia Dortmund’s formidable attack in September’s Champions League tie.

Another outstanding performance from the 20-year-old was capped by a goal that his attacking colleagues would have been proud of, as he drove into the area before curling a shot into the far corner with his wrong foot. His combination with Ramsey on the right provided the Gunners with stability in defence and menace going forward. Giving away a penalty was unfortunate, but Bellerin won’t be the last player to be undone by the trickery of Sterling.

With Bellerin on one flank and Nacho Monreal on the other Arsenal’s defence also looks more balanced than it has since the days of Sol Campbell. The right-back’s pace allows him to cover for Per Mertesacker whilst Monreal’s experience playing in the middle has made him a more complete defender. With Francis Coquelin shielding Arsenal could well be on their way to more solid performances against top sides. Getty 5/5 Only one of these sides will be in contention for the title next season As delighted as Wenger will be to see his side pick up another commanding win over a rival he must be left wondering what might have been if Arsenal had only been able to find this purple patch at the start of the season.

With a transfer window ahead to address the few issues that remain in his squad, a world-class goalkeeper being the most pressing, the Gunners manager may soon be able to mount his first true title challenge in over a decade.

Their forthcoming game with Chelsea may come too late for them to catch the Blues but it represents a perfect opportunity to lay down a market for 2015/16. For Brendan Rodgers the picture was already unclear before Sterling cast his future at Anfield into doubt. Both his squad and his first 11 seem some way short of the quality to challenge for the Champions League, let alone to reignite memories of last season’s unlikely charge for the top.

Despite seven goals in his last six appearances, the slick Frenchman still has five goals fewer than his Chelsea and Tottenham counterparts, but while he is unlikely to topple that duo to finish as Golden Boot winner, the rate at which he has scored his goals is more impressive than Costa's 0.84 and Kane's 0.81. If we exclude goals scored from penalties, Kane's goalscoring rate falls to 0.73.

While Giroud has inspired an Arsenal resurgence since returning from his lay-off, another player who would have liked to have seen more playing time this season is Newcastle's 11-goal forward, Papiss Cisse. The Senegalese international has been plagued by injury and suspension this season, yet has delivered 0.82 non-penalty goals for every 90 minutes he has spent on the pitch, ranking him the third most prolific striker just behind Giroud and Costa.

While Cisse would be the surprise inclusion on this list, one name is conspicuous by its absence. You would be forgiven for expecting Sergio Aguero to feature in any discussion of predatory strikers, but the Manchester City forward falls short of his rivals when comparing non-penalty goals per 90 minutes. The Argentine may have 17 goals to his name this season, making him a credible contender for the Golden Boot, but excluding his five penalties sees Aguero's strike rate fall from 0.75 to 0.58 goals per 90 minutes - well behind the rate maintained by Costa, Kane and Giroud.

:: The Engine Room is the Press Association's weekly data-driven football review in which our MatchStory team analyse the numbers behind the topical stories to add context and insight. MatchStory is the Press Association's unique approach to delivering insight from football data. See our website (www.matchstory.co.uk) and Twitter account (@MatchStory) for more.