APRIL 19 ― One of the great things about sport is that you just never know.

Often, we think we know. And a lot of the times, what we think we know ends up being correct. But sometimes, even the things we think we know the most turn out to be erroneous.

Last weekend, for example, we thought we knew that Jordan Spieth was going to win the US Masters golf championship when he held a five-shot lead with just nine holes to play in the final round.

But then his form mysteriously evaporated and Danny Willett suddenly found himself crowned the most unexpected of champions.

At the start of this month, we also thought we knew that Barcelona were going to win the Spanish league title, and that they were going to win it easily.

The Catalan giants were nine points clear of second-placed Atletico Madrid and had not been beaten in 39 games, dating back nearly six months. La Liga’s top spot, it appeared absolutely certain, was in the bag.

But then Barca lost against Real Madrid, lost against Real Sociedad and, on Sunday night, lost their third consecutive league game for the first time in 13 years as Valencia triumphed at the Nou Camp. And so now, from a position of not even seriously challenging, Atletico Madrid are level at the top with Real Madrid just one point behind.

The most striking aspect of Barcelona’s dramatic collapse is the sudden ineffectiveness of their superstar forward line, Lionel Messi, Luis Suarez and Neymar.

For the last 18 months, ever since Suarez moved to Spain from Liverpool, they have been more or less unstoppable. Last season, which ended with their team winning a league, cup and European treble, they combined for a ridiculous tally of 122 goals ― the highest number scored in a season by a trio in Spanish football history.

And for much of the current campaign they appeared to be set to smash their own record, moving into treble figures with plenty of games still remaining ― in March alone, they scored 13 goals in just five games, and everything was pointing towards another glorious season finale for a team which pretty much everybody acknowledged at the best in the world.

But now, just as suddenly as golfer Spieth’s swing suddenly deserted him, Barca’s “MSN” have dried up. In the last five games, they have only scored three goals ― Suarez two, Messi one and Neymar none at all ― and their season appears to be in the middle of meltdown.

While Barca have been dropping points at an alarming rate, their nearest rivals have been greedily hoovering up victory after victory: Atletico have claimed maximum points from their last three games, while Real’s walk in the park against Getafe on Saturday was their sixth straight league win.

So where will it all end? The season only has five games remaining and, if the pattern of the last few weeks is repeated, Barca will finish way back in third as the two Madrid teams battle it out for supremacy.

Not so fast, though. The lesson we have just learned, after all, is that in sport you just never know, and it is far too soon to write off Barcelona ― and far too soon to assume that Real and Atletico will keep on winning.

In the same way that Messi, Suarez and Neymar have suddenly stopped scoring, they can very easily start scoring again ― they are too good players to endure a barren spell for much longer.

We can speculate and analyse and offer educated guesses, but in truth nobody knows why they have stopped performing at their peak levels.

When I worked at Reading Football Club, our manager Steve Coppell would always say whenever the team hit a bad run of form, “If I knew why it was happening, I’d do something about it.”

At first, that sounds like a disappointing answer from a vastly experienced manager who was supposed to be able to assess exactly where and why his team was going right and wrong. But really it was just an honest acceptance of the fact that nobody really knows exactly why teams and players sometimes lose their form. It can just happen.

And so, as we approach the climax of the European football season, we should take nothing for granted. As things stand, Leicester City look certain to win the English Premier League title, and Bayern Munich are near certain champions of the German Bundesliga with a seven point lead over Borussia Dortmund with just four games remaining.

Most probably, Leicester and Bayern will indeed end up winning their respective leagues. They are a long way ahead and it would be hard for them to lose it from here.

But the reason we keep on watching sport until the very end is that strange things can happen, and you never really know ― however much you think you know – what the outcome will be. Just ask Barcelona.

*This is the personal opinion of the columnist.