Where might the Revierderby be won and lost?

1) The Haaland factor

A contender for the title of the best No.9 in world football not named Robert Lewandowski, Haaland will take some stopping. The 20-year-old has already scored five times this season, whilst landing three assists - including the match-winning pass for Marco Reus against Hoffenheim on Matchday 4. All told, he has struck 17 times in 19 Bundesliga appearances since making the switch from Red Bull Salzburg at the turn of the year.

It took Lewandowski 47 matches to score as many Bundesliga goals.

Haaland's one-track mind enables him to focus purely on the task at hand. Unlike some of his contemporaries, he doesn't need his ego massaging by 70,000 spectators to get the job done. The Norway international paved the way for a 4-0 rout in the previous Revierderby - the first of its kind to be played without fans in attendance - and calmly sunk an effort past Manuel Neuer in Dortmund's behind-closed-doors narrow Supercup defeat to Bayern Munich.

His ruthless streak - laid bare by six multiple-goal showings against Augsburg, Cologne, Union Berlin, RB Leipzig, Borussia Mönchengladbach and Freiburg - teases a long shift at the office for Schalke. The Royal Blues have shipped 53 goals since recording their last league win on 17 January 2020, including eight away to Bayern on the opening weekend of the new campaign. They haven't kept a clean sheet in 16, and few would give them a prayer of bucking the trend against Haaland and Co.

2) Reyna's Revierderby?

Leading the supporting cast, at least statistically, is young Reyna. The 17-year-old has been a revelation in the early part of his first full season of Bundesliga football, producing one goal and four assists in four league starts. Only Haaland has had a bigger hand in Dortmund's eight league strikes, with three of his five efforts coming via the boot of his prodigious playfellow. "He's the American dream," quipped the Norwegian earlier this season.

Those at BVB waxed in similarly lyrical tones about Christian Pulisic during his five-year stint at the Signal Iduna Park. The USMNT playmaker tore up the history books after being handed his Bundesliga debut by Thomas Tuchel at 17, supplying 19 goals and 26 assists in 127 competitive outings before switching to Chelsea in summer 2019. There were some seminal showings along the way, but not once in seven attempts did he succeed in putting his star-spangled paw print over Germany's fiercest rivalry.

Although countryman Weston McKennie fared only marginally better, playing his part in two wins for Schalke to Pulisic's one in black and yellow, a first Revierderby goal or assist by an American national is still up for grabs. Reyna - comparable to Pulisic in so many ways, but arguably ahead of the curve - could be the man to buck the trend and post the next significant milestone of his still young career in the fast lane.

3) A tale of two (or more?) keepers

Frederik Rönnow can expect to be a busy bee regardless. Schalke's second-choice goalkeeper made his first start since joining the club on loan from Eintracht Frankfurt in the 1-1 draw with Union Berlin on Bundesliga Matchday 4, repelling a league-high six shots. That's twice as many as he was forced to make after replacing the injured Ralf Fährmann midway through the 4-0 defeat to leaders RB Leipzig, all goals falling prior to his introduction.

The case for Rönnow exerting a calming influence on the Bundesliga's most porous defence in the calendar year 2020 is difficult to ignore, when you consider the 14 goals shipped by Fährmann in a full game more playing time. Marwin Hitz is the root cause of like-minded murmurings on the black-and-yellow side of the Ruhr district divide, following his back-to-back shut-outs in wins over Freiburg and Hoffenheim. To drop him in favour of fit-again No.1 Roman Bürki would be somewhat against the grain.

Lucien Favre knows four hands are better than two, but selecting the safest pair of mitts to face a Schalke team that has nothing to lose and everything to gain by shooting on sight and lumping balls into the box poses a quandary. An excellent shot-stopper - Hitz boasted the third best save percentage in the Bundesliga in his final year at Augsburg - BVB's able deputy also has two inches on his countryman and kept Die Knappen at bay in last season's reverse fixture. Another derby date could be his destiny.

4) Dortmund firing on all cylinders; Schalke's cold start

Stepping in as the last line of defence behind one of the most exciting Dortmund teams in living memory must make Hitz's job a whole lot easier. Other than their uncharacteristically flat showing in the Matchday 2 loss to Augsburg, Favre's class of 2020/21 have played some sensational stuff and pound-for-pound would appear to pack more of a punch than their 2018/19 and 2019/20 counterparts, who finished two and 13 points adrift of champions Bayern respectively.

The likes of Emre Can, Mats Hummels, Raphael Guerreiro, Thomas Meunier, Lukasz Piszczek and Axel Witsel bring bags of experience to the table - a prerequisite for any wannabe title winner - but it's BVB's new wave that has got everyone talking. As well as Haaland and Reyna, die Schwarzgelben have a 20-year-old creative tour de force in Jadon Sancho, a Belgium international stepping out from his acclaimed older brother's shadow in Thorgan Hazard, and a midfield star so bright that former club Birmingham City retired his jersey number when he joined Dortmund in the summer at the age of 17: Jude Bellingham.

If that wasn't enough talent to make your eyes pop, 15-year-old wunderkind Youssoufa Moukoko - who is fast nearing 150 goals at youth level - could make his Bundesliga debut as early as next month, when he turns 16. It's almost as if the Dortmund hierarchy have seen the success treble winners Bayern had blooding Canadian teenager Alphonso Davies at the highest level last season and raised them tenfold.

Watch: Dortmund's next generation under the microscope

Schalke haven't been quite as fortunate in recent years, even if their vaunted Knappenschmiede academy can count Neuer and Leroy Sane among its celebrated alumni. Germany midfielder Suat Serdar - the club's seven-goal top scorer last term - is out injured. Amine Harit - who struck six times in 2019/20 - hasn't found the net in the league since 23 November 2019. US international midfield general McKennie has been loaned out to Juventus, while defensive bedrock Ozan Kabak is suspended.

Although Frankfurt loanee Goncalo Paciencia rode to the rescue with the equaliser against Union last time out, one point and a goal difference of -14 after four matches still represents Schalke's worst ever start to a Bundesliga season. If they fail to snap their unwanted club record 20-game winless run in Dortmund, the Royal Blues will only have Tasmania Berlin ahead of them in the Bundesliga's all-time barren department. Among their catalogue of dubious distinctions, the capital outfit went 31 games without a top-flight win between 14 August 1965 and 21 May 1966.

5) A history of upsetting the apple cart

Happily for Schalke, logic tends to go out of the window in matters of a Ruhr district derby kind. With one point from four matches this term, 16 goals conceded in that time, and a just eight scored in 21 league matches in 2020, the Royal Blues shouldn't have a prayer. Dortmund have won three, accounting for Gladbach, Freiburg and a Hoffenheim unit that ended Bayern's 23-game winning streak, whilst plundering 30 more goals than their near neighbours since the turn of the year.

Against almost any other opposition, Dortmund would be looking at the contest as a home banker, but history has taught them not to count their derby chickens until they've hatched. On Matchday 13 of 2017/18, BVB led Schalke 4-0 after 25 minutes. Even when Guido Burgstaller and Harit halved the deficit with 25 to go, the three points appeared as good as theirs, but then the unthinkable happened. Daniel Caligiuri added a third in the 86th minute, before Naldo powered in an injury-time equaliser.

Watch: Highlights of the true Mother of all Derbies

It's not the only time Schalke have assumed the role of pooper at Dortmund's party. With four fixtures left on the 2018/19 Bundesliga calendar, BVB - a point off top spot in second - had genuine designs on ending Bayern's six-year reign as champions. The Royal Blues, for their part, made the 22-mile journey east peering nervously over their shoulders at the relegation zone. Mario Götze's early strike threatened to plunge them closer to the mire - only Huub Stevens' men hadn't read the script. A 4-2 turnaround ultimately saved Schalke's bacon, whilst all but ending Dortmund's title aspirations.

The Revierderby annals are littered with cautionary tales. There could be 16 places between the two rivals in the Bundesliga standings - correctly predicting the outcome is still something of a lottery. And while victory might not change lives in the same way a Megamillions jackpot would, it does have the power to drastically transform the derby winner's fortunes. As pre-match favourites Dortmund know only too well: write off Schalke at your peril.

Chris Mayer-Lodge