Ahead of this weekend's Scottish Cup semi-finals, BBC Scotland spoke to former managers of the teams considered underdogs in each tie to discuss how the games might play out and how they can produce a shock.
Hibernian v Falkirk: Former Falkirk manager Steven Pressley
One of the strengths of Hibernian is they're a physical, very aggressive team, so the one thing Falkirk mustn't do is turn it into a game of physicality.
Of course that will always be part of the game and they have to deal with that, particularly at set-plays, but Falkirk have to impose their passing philosophy on the match, because I believe they're the better footballing side.
To do that, they have to believe in the philosophy that's been preached to them on a daily basis for many years, to take and use the ball under pressure.
Falkirk have players who are not only creative, but also energetic and fit - guys like Blair Alston, David Weatherston and Thomas Grant - to allow them to link up with Lyle Taylor.
As long as they pass in the way they've been coached, they'll always be in touch with Lyle. The problem will come if they get penned in and don't show the courage to play under pressure - that's when Lyle can become isolated.
Obviously one of Hibernian's key figures is Leigh Griffiths. They're very reliant on him so Falkirk's centre backs and also Stewart Murdoch - as the defensive midfielder - will be important to try to nullify the threat of Griffiths, not only to cut off the supply to him but also to smother him when he gets possession.
Falkirk can't afford to allow him to be left one-on-one with their centre backs.
One very interesting aspect for Hibernian will be how they deal with being favourites and not having won the trophy for so many years. Falkirk go into the match with no pressure on their shoulders.
Hibs are hard-working and organised, but they generally don't control games, they generally play on the counter-attack, trying to expose teams on the break. That's when Hibs will hurt you, so Falkirk's organisation on losing the ball is crucial.
Dundee United v Celtic: Former Utd manager Peter Houston
I'd expect Jackie McNamara to stick with the option of one lone striker, almost certainly Jon Daly, and two wide players, probably Gary Mackay-Steven and either Stuart Armstrong or Ryan Gault.
They'll certainly, I think, use three tight in the middle of the park, with the two wide men dropping in to make it a five when they lose possession.
The wide guys will be allowed to drop into areas where they think they can hurt Celtic, so Mackay-Steven will look to drag the right-back deeper and in the park a bit, to confuse Celtic's midfield and if they go 4-4-2, it'll force them to narrow the midfield a bit.
They'll also be allowed to switch wings, drop in behind Daly and go beyond him too. I believe Jackie has given the front players license not to worry about the defensive side so much and save energy for making forward runs.
Good deliveries from them and the fullbacks (probably Keith Watson and Barry Douglas) could be crucial because, on his day, Daly can score goals against anybody.
The pace of Mackay-Steven and Armstrong, if Celtic hold a high line, which I'd expect them to do, means these guys can get in behind the defence, as they have already against Celtic, and cause them problems.
Perhaps most importantly, they have to avoid losing goals and one thing Dundee United don't have now, compared to years gone by, is a lot of height in the team. I liked zonal marking, Jackie has been using man-marking, but both ways United have lost goals and one of the best teams in the league for set-pieces is Celtic.
They vary them well, they've got height and aggression from Victor Wanyama and Georgios Samaras, for example, and superb delivery from Charlie Mulgrew.
The threat from Celtic comes from all over the park. They're at their best when they start at a high tempo. Their full-backs will be bombing forward all afternoon. Emilio Izaguirre is like a left winger, pushing right up the park.
Gary Hooper will look to drop into holes, which he's great at doing, and then getting turned for a strike at goal and Kris Commons is high on confidence and playing well just now.
If you're the United manager and thought too much about how good Celtic are, you'd be worried about how many you're going to lose by. But Jackie will be positive, ask his players to believe in themselves, to pass the ball and if they can avoid losing an early goal, they have the ability to win the game.