What makes a title-winning team? Good players? A great manager? A humongous transfer budget?
All of the above might be vital ingredients in creating a side capable of challenging for top domestic honours, but there's one quality that shouldn't be underestimated in the race for Premier League glory - confidence.
Chelsea have some fantastic players, a manager with a proven track record and a billionaire owner to bankroll their summer spending. But after a demoralising Champions League exit last week, they appear to be lacking the belief to save their season.
The Blues' most optimistic fans might have seen their defeat at the hands of Jose Mourinho's Inter Milan as a blessing in disguise - a chance to focus on regaining the title and retaining the FA Cup.
And most would've expected a positive reaction from John Terry and co after their lacklustre display at Stamford Bridge last week, but they provided the exact opposite during an uninspiring draw away at Blackburn yesterday afternoon.
If Carlo Ancelotti's men had progressed through to the last eight of Europe's most prestigious club competition they would've had to contend with at least two more games, possibly rising to five if they'd gone all the way to the final.
But while their involvement in the FA Cup would've given them a more demanding schedule than title-rivals Arsenal and Manchester United - a win over Inter could've given them so much more than just a few extra games.
Trailing 2-1 from the first-leg at the San Siro, Chelsea needed to deliver the sort of European performance that has seen them reach at least the semi-finals in four of the last six seasons.
Instead they went out with a whimper, a shadow of the side that has knocked-out the likes of Barcelona, Valencia and Liverpool in recent seasons.
If they'd managed to overturn their first-leg deficit last Tuesday, then I've got no doubt we would've seen a completely different Chelsea at Ewood Park on Sunday.
Buoyed by a good performance and the achievement of reaching the last eight, Ancelotti's men would've brushed aside injury-hit Blackburn.
But after crashing out of a competition they'd put so much emphasis on, the players looked both sluggish and nervous – a worrying sign with just eight league games and a challenging FA Cup semi-final against Aston Villa left to play.
Topping-off a nightmare week for the west-Londoners were moral-boosting wins for ten-man Arsenal, and Manchester United who came from behind to beat fierce rivals Liverpool.
Chelsea have the players and the manager to win the league – that has never been in question. But whether they have the belief, confidence and winning-mentality to claim another Premiership crown is definitely up for debate.
READ JOE STRANGE EXCLUSIVELY AT FOOTBALL.CO.UK EVERY MONDAY