League form is famously thrown out of the window when cup games come around. So Stephen Tudor instead studies the form of the cup.
"The bad news for both teams is that the winner will probably meet Manchester City in the next round."
Determining the outcome of a FA Cup tie can be notoriously difficult.
League form acts as a rough guide at best while it amounts to guesswork as to which managers will field strong line-ups and who will seek to rest key players. This is especially true of the fourth round when some leading sides begin to take the competition seriously but others - particularly those with relegation concerns or promotion aspirations - continue to view it as a distraction.
Then there are the intangible factors complicating matters further. No, we're not talking about the 'magic of the cup' here: nothing as romanticised as that. It's simply that in a one-off cup game, when one team might fancy it more than the other, anything can happen. Chorley can beat Derby. Crawley can put three past Leeds.
Finding probabilities amidst all this uncertainty can take you down one path, then another so it makes sense to step back and try a different metric altogether, in this instance highlighting the teams and gaffers who have a proven track record in this tournament.
They have shown before that they know the way to the fifth round. It's only logical then to follow them.
At face value the Lions have a tricky test this weekend hosting a Bristol City side who are seven places above them in the Championship. The Robins have notably improved under Dean Holden this term and have been in the play-off mix from the off.
But then you acknowledge that Millwall ran out comfortable winners at Ashton Gate last month despite ceding much of the possession. City typically struggle against physical opposition and here was no exception with Lions boss Gary Rowlett admitting afterwards: "Our aim was to get the ball forward early and win the second balls."
It matters too that the Robins have a poor to woeful pedigree in the FA Cup, going out at the first hurdle 15 times in the last 20 years. Their best ever return was a quarter final spot when Harold Wilson was Prime Minister.
Whereas with Millwall the very opposite applies because for whatever reason something special tends to happen whenever they enter the FA Cup fray. In 2004 they surprised an entire nation reaching the final before losing to Manchester United. Nine years later they got to the semis. Since 2017 they have twice overcome the odds and made it to the last eight.
For a club that has spent all but two of its 136 years residing beyond the top-flight it all adds up to a staggering achievement.
A happy habit for Hughton
When assessing a club's cup credentials how far back do we go?
Does Blackpool's three trips to Wembley post-war, with a team featuring the colossal talents of Matthews and Mortensen have any bearing at all on the Tangerines' trip to Brighton this Saturday? Of course not. The only thing linking the club then and now is their name and colour of kit.
Whereas with Brighton, their progress to the quarter finals and semi finals in 2018 and 2019 are relevant indeed and with that know-how embedded in their DNA the Seagulls will fancy their chances against League Two opposition.
The man who orchestrated Brighton's fine cup runs was Chris Hughton who is freshly installed at Nottingham Forest and if the likeable gaffer knows how to navigate a path through the rounds it's fair to say his new employers do not. Forest have only got past this stage of the competition twice since 1996.
It's a formidable task facing the Tricky Trees, away to a team in Swansea who boast the meanest defence in the Championship but countering this Forest side looks a very different proposition since Hughton arrived.
The bad news for both teams incidentally is that the winner will probably meet Manchester City in the next round.
A break for the Blades
For many years Chris Wilder's managerial record in the FA Cup was nothing to write home about until last season, when Sheffield United parlayed their excellent league displays and made it to the quarters.
As decent an achievement as this was it pales however to United's two excursions to the semi-finals this century, the first of which is best recalled by an extraordinary save by David Seaman. The second saw the third-tier outfit lose to Hull in a 5-3 classic.
Unquestionably then the Yorkshire side have contributed greatly to the competition in recent times. They certainly have the pedigree to go far.
There is another consideration too, one that involves their awful campaign to date that has rooted them to the foot of the Premier League. Might the cup be viewed as a welcome respite from their weekly woes?
We have seen this happen time and again. In the last four years three sides who ultimately dropped out of the top-flight reached the final eight. In 2013 Wigan Athletic lifted the trophy just days before having their relegation confirmed while three years earlier Portsmouth's fate was already sealed when they lost narrowly to Chelsea in the final.
Don't discount the Blades based on their league showings. On cup weekends it could conversely be a plus.
A love affair for Lamps
Chelsea have appeared in 42.8% of FA Cup finals in the 21st century, winning six of them. That's not just a club with a proven track record in the tournament. That's a club whose relationship with a tournament runs so deep they probably have matching tattoos.
Surprisingly, only one of these successes was presided over by Jose Mourinho - though he also has a runner-up medal from his time at Manchester United - and the always enigmatic coach takes his Spurs side to Wycombe on Monday in a year ending in one. The superstitious among us will know what that means.
Back at Chelsea, their present boss and former midfield legend Frank Lampard lifted the cup on four occasions as a player and has already guided his side to a Wembley appearance, losing to London rivals Arsenal back in August. His squad of superstars will be desperate to go one better this time.
As for Lampard himself, perhaps his fond memories of the competition will mean he views this weekend's hosting of Luton as a relief from the speculation regarding his job security after losing four in eight in the league.
No Pep talk for Cheltenham
As obvious choices go this takes some beating but how can we overlook a coach who has lost just four from the 45 domestic cup games he's been involved in since taking the reins at the Etihad.
Granted more than half of these have been in the League Cup but it is illustration that Pep Guardiola very rarely weakens his side for knockout competitions irrespective of opposition. It is doubtful he will veer from this ethos at Cheltenham Town.
If that adds an extra dimension of fear for the Robins it only gets worse because City under the demanding Catalan have consistently shown scant mercy when facing underdogs. On the 20 occasions they have encountered sides beyond the Premier League the Blues have ruthlessly fired home 61 goals with a 7-0 and 9-0 included.