The uniquely hectic winter schedule is part of what makes the Premier League the most exciting and demanding top flight in world football, and this year it's thrown up a real gem in Arsenal's visit to West Ham.

Featuring two London clubs of completely contrasting styles, this fixture often produces memorable moments. But there's more on the line than ever this year due to the Hammers' rise to fourth in the Premier League table - a league standing that's become synonymous with the Gunners over the last decade.

The lower-placed north Londoners will be keen to close the gap on the East London side side, but West Ham will fancy their chances, having won six of their last seven league fixtures at Upton Park.

That being said, fixtures of such festive feistiness are often decided by who dominates the individual battles, so here's FIVE that could decide the outcome on Sunday.

ANDY CARROLL VS PER MERTESACKER

Carroll

Anonymous during Arsenal's 3-2 defeat to Stoke City and out-jumped by Martin Skrtel for a last-minute equalizer against Liverpool, Arsene Wenger has claimed German international Per Mertesacker is struggling for motivation this season after the highs of his World Cup campaign.



But if the BFG found Peter Crouch and Skrtel too tough to contend with in the air, he's in for an even rougher ride against West Ham. Star striker Andy Carroll, amid a superfluous run of form, has reaffirmed himself as the Premier League's leading aerial combatant - by quite an incredible distance - since returning from injury in November, as detailed below:



Carroll headers



On top of that rather sensational statistic, the England international has rediscovered his scoring touch too - take this beautiful chip against Leicester City for example, making it three goals and one assist in his last three Premier League appearances:





Carrol's aerial dominance is an inevitability, so for Arsenal's defenders it's a case of damage limitation. The Gunners will be hoping Laurent Koscielny can pass a late fitness test - otherwise, they're set for a troubling mismatch if 5 foot 10 full-back Mathieu Debuchy is called upon as an emergency centre-half again.

STEWART DOWNING VS MATHIEU FLAMINI

Stewart Downing 1

Stewart Downing is enjoying a new lease of life in central attacking midfield and arguably the most productive form of his career, grabbing a talismanic four goals and six assists in 16 Premier League outings. It would be naive to think the England international isn't capable of hurting Arsenal - currently, only Chelsea's Cesc Fabregas is creating more chances per match in the Premier League than the 30 year-old, as detailed below:



Downing chances created



He'll be directly up against Mathieu Flamini, who understandably took a lot of criticism for Arsenal's 2-2 draw with Liverpool last weekend. The Frenchman is a shadow of the player of his original Gunners tenure but hardly received adequate support from midfield partners Santi Cazorla and Alex Oxlade-Chamberlain at Anfield.



Even so, with Mikel Arteta, Jack Wilshere, Aaron Ramsey and Mesut Ozil all absent until the New Year, the ad-hoc situation in the middle of the park is unlikely to change any time soon.



Flamini really needs to up his game when facing West Ham, having failed to make a single successful tackle and recorded a pass completion rate of just 73% against Liverpool, or it will be another afternoon of Downing delight for the East Londoners.


ALEXIS SANCHEZ VS GUY DEMEL

Sanchez

A highly versatile and talented attacker, it remains to be seen how Arsene Wenger will opt to utilise £35million signing Alexis Sanchez against West Ham.



But he's been Arsenal's most potent entity going forward this season by quite some distance, as detailed below:



Sanchez vs Arsenal



And for that reason alone, it's likely he'll be deployed against Hammers right-back veteran Guy Demel.



Gunners loanee Carl Jenkinson has emerged as the first choice No.2 at Upton Park this season, but unavailable to play against his parent club, the 33 year-old will assumedly be thrust back into first team affairs.



He's certainly got the trust of Sam Allardyce, having served under him for three-and-a-half campaigns. But general ring-rust, having not started a fixture since September, in addition to Demel's naturally waning pace, makes him a weak link in West Ham's otherwise resolute defence.



If Sanchez brings his A-game, he'll run rings around the retired Ivory Coast international all afternoon.

ALEX SONG VS SANTI CAZORLA

Alex Song

With Arsenal's injury issues seemingly having no end, Santi Cazorla looks set to retain the No.10 role for the Gunners' visit to Upton Park.



The Spain international's never quite rekindled the form of his inaugural Premier League season but has put in a number of decent performances this term - particularly against Newcastle where he netted a brace, including this cheeky penalty:





His ambipedial feet should be a huge advantage in the central role - providing he can get past West Ham's Alex Song.



There's subplots here aplenty; of course, the Cameroon midfielder is a former Gunner and will keen to impress against his former club, but the story is further enriched by recent criticisms of Wenger's decision not to re-sign the Barcelona loanee during the summer, despite Arsenal's obvious need for a holding midfielder.



Instead, Song's class, quality and experience has brought West Ham to a whole new level and he's already become a leader amongst their starting XI.



This is Song's opportunity to prove Wenger wrong - so Cazorla should expect the African enforcer to be in top form.

OLIVIER GIROUD VS WINSTON REID

Giroud

Olivier Giroud is proving himself to be more vital to the Arsenal cause than ever this season, with five goals in just eight Premier League appearances. The Frenchman's scored past Liverpool, Manchester United, Everton and Newcastle this term, perhaps dispelling the myth that he struggles to perform against the bigger clubs.



West Ham are a rather different proposition however, and it's the 28 year-old's ruggedness, rather than his quality, that Arsenal require most on their East London visit.



Centre-back Winston Reid is one of the Premier League's best outside of the top four - he's even been linked with a move to the Emirates in January - with an incredible physical presence and a simple-yet-effective style.



He'll give Giroud little room for manoeuvre and will likely dominate in the air. But if Arsenal are to generate anything going forward, the France international must hold off the New Zealand skipper as much as possible to bring the Gunners' impressive midfield talents into the game.



Failing to do so, and it will be eternally difficult for the north Londoners to get forward with any pace or intent.