The Premier League's uniquely demanding winter schedule is part of what makes it the best top flight in world football, and it's thrown up a classic fixture on Sunday in Everton's visit to St. James's Park.

It's been a tough start to the campaign for the Toffees with second-season syndrome clearly kicking-in for Roberto Martinez; instead of affirming themselves as Champions League contenders, they're currently battling to make it into the Premier League's top half.

Meanwhile, it's been a predictably turbulent season for Newcastle, but they'll fancy their chances at St. James's. Everton have been losing at both half-time and full-time in their last three Premier League away visits, whilst the Magpies have lost just twice at home since the summer.

Matches of such festive feistiness are often decided by who dominates the key battles however, so with that in mind, here's FIVE that could eventually determine the outcome.

AYOZE PEREZ VS PHIL JAGIELKA

Ayoze Perez

A contest of Spanish flair against English brawn, striker Ayoze Perez' battle with Everton skipper Phil Jagielka represents the contrast of two completely different styles.

The young Spaniard reportedly rejected offers from Barcelona and Real Madrid to move to Tyneside this summer and is living up to all the hype with four goals in just eight Premier League starts.

The 21 year-old's netted just once in his last seven - a consolation in the Magpies' 4-1 defeat to Arsenal - but he'll fancy his chances against the Toffees, who currently boast the joint-third worst goals conceded column in the Premier League.

SEAMUS COLEMAN VS SAMMY AMEOBI

Everton v Aston Villa - Barclays Premier League

Having made the left-wing slot in Newcastle's starting XI his own this season and particularly impressed against Sunderland last weekend, it's likely Sammy Ameobi will retain his spot for the Everton clash on Sunday.

The brother of Shola is hardly the most orthodox winger, measuring in at almost 6 foot 5, but he's the Magpies second-best creator this season with two assists and their second most proficient dribbler at 1.7 successful take-ons per-match - two stats only bettered by Daryl Janmaat and Moussa Sissoko respectively.

He'll be up against arguably his toughest test yet in Everton's Seamus Coleman, who has emerged as the best attacking right-back in the Premier League in the last 18 months, amassing eight goals and three assists in his last 50 league outings.

This battle will be a delicate balancing act for both players. Coleman will bomb forward relentlessly so Ameobi needs to make sure he's tracking every run, but that intrinsic ploy has become a bit of a dogma for the Toffees this season and it will undoubtedly leave space for the Newcastle winger to exploit on the counter-attack - especially if Everton are caught dwindling on the ball in midfield.

Romelu Lukaku vs Fabricio Coloccini

Lukaku 1

It's not been the best of seasons for Romelu Lukaku compared to his usual prolific standards, finding just six goals in 16 Premier League outings.

But let's not forget what the Belgium international is capable of; he's a 6 foot 3 battering ram of goalscoring prowess and, perhaps most dangerously of all, comes with the youthful, arrogant swagger of a 21 year-old with the world at his feet.

His physical presence is enormous and Newcastle will have to prepare accordingly. Magpies skipper Fabricio Coloccini will likely be his predominant marker as a battle-hardened, experienced and powerful centre-half, but the Argentine may struggle to nullify Lukaku whilst simultaneously trying to organise Newcastle's ever-chaotic back four.

MOUSSA SISSOKO VS GARETH BARRY

Manchester City v Newcastle United - Capital One Cup Fourth Round

Moussa Sissoko's really beginning to stand out as a focal point of the Newcastle starting XI, excelling in the No.10 role almost as an anti-type, replacing precision passing and trickery with power and pace.

He's strong defensively and a real handful on the counter-attack, so the task of stopping him will largely fall to Everton's Gareth Barry.

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The former England international has struggled to replicate the incredible form of his Goodison loan spell this year, but his experience and quality as a Premier League enforcer remains undoubted.

That being said, the 33 year-old gets caught in possession at least a couple of times per match at the moment - Sissoko, through his brawn and tenacity, is the perfect candidate to cause Barry further problems.

ROSS BARKLEY VS CHEICK TIOTE

Ross Barkley

Just when doubts were beginning to surround Everton prodigy Ross Barkley, he goes and scores this absolute belter against QPR:

There's been plenty of talk about his role in the starting Xi recently, and whether the England international's future lies in central or attacking midfield.

Either way however, his defining gift as a footballer is the power, skill and confidence in which he bursts forward in central channels to run at back fours, usually resulting in a shot at goal or a created chance for one of his team-mates.

Therefore, Newcastle's Cheick Tiote will have to keep particular eye on the 21 year-old midfielder, especially when he's bursting through the middle of the park. The Ivory Coast international is arguably the Magpies' most impressive entity on paper however, so Toon fans will fancy his chances of keeping Barkley quiet.

That being said, Tiote's ill-discipline could be a real issue against Everton. He averages the second-most fouls per match of any Premier League player:

Tiote fouls

But the Toffees' options from set pieces - namely, Leighton Baines, Kevin Mirallas and Ross Barkley - are amongst the most prolific in the Premier League.