For Premier League clubs outside the top six, one result can change everything.
Take West Ham, who could move into the top half of the Premier League with a victory at Swansea on Saturday.
Lose, however, and the Hammers will be level on points with their opponents, who are currently inside the relegation zone on goal difference.
The game is a big one, and the Swans come into it with confidence, having won six successive home matches in all competitions.
Three of those were in the FA Cup against Championship sides, however, while that sequence’s most recent fixture – the 2-0 win over Sheffield Wednesday in midweek – means West Ham come into the match as the fresher of the two teams.
It is difficult to call the result, but it can be said with certainty that there will be goals at both ends. West Ham have scored in eleven successive Premier League matches, while Swansea have done so in their last six at home in all competitions.
The Hammers have several goalscoring threats, with Michail Antonio, Mark Arnautovic and Chicharito all finding the net in recent weeks.
The best value is Arnautovic, the club’s joint-top scorer this season with seven and likely a guaranteed starter at the Liberty Stadium.
Swansea were unusually open in last weekend’s 4-1 defeat at Brighton – their first defeat in 10 matches in all competitions – and the Austrian’s pace and power can be just as decisive if the same happens again this weekend.
That is likely to be later on in the match when the game has opened up. Carvahal’s teams are naturally cautious – he only went for it in the second half at the Amex when his side were 1-0 down – while the strength of this West Ham side is on the counter.
But David Moyes’ side will have to defend well throughout. Swansea have scored inside the last 10 minutes in each of their last four home matches.