Who scores the opening goal at the New York Stadium tomorrow couid have a massive bearing on the final result.
That's if Pompey's stats this season are anything to go by.
When the Blues have scored the opening goal in their League One fixtures this term, they've went on to win 86 per cent of the matches they been involved in.
That's a staggering 12 wins from a possible 14 this term, with last weekend's 1-1 draw with Scunthorpe and the 2-1 defeat to Bristol Rovers at the end of 2017 going against the norm.
Who scores that opening goal for Kenny Jackett's men could also prove pivotal for the superstitious among us.
That honour has fallen to Brett Pitman five times in the league this season - against Rochdale, Wimbledon, Fleetwood, Blackpool and Southend.
And yes, on each occasion Pompey have gone on to win the game.
The Blues' record when they've been on the receiving end of an opening goal doesn't make for good reading, though.
Only once have they managed to overcome such a blow to go on and win the game.
That came during last month's 3-1 victory over Northampton at Fratton Park.
Chris Long opened the scoring for Jimmy Floyd Hasselbaink's side after 36 minutes.
But the Cobblers' lead didn't last long, with Matty Kennedy equalising five minutes later, before an Oli Hawkins double settled matters.
Apart from that game, however, the Blues appear to there for the taking when they concede first.
From those 14 matches - including the FA Cup defeat to Luton - they went on to lose 11, with draws against Walsall (1-1) and Wigan (1-1) sparing their blushes slightly.
And in seven of those games Pompey failed to score, leaving their opponents in total control.
Losing at half-time doesn't seem to suit Jackett's men, either.
They've been behind nine times this season at the halfway stage of a match and only once recovered to get something from the game - with Conor Chaplin scoring the equaliser at Wigan in the 76th minute.
For the record, Pompey have also yet to register a goalless draw this season.