Andy Murray at a loss to explain shock Indian Wells exit to world number 129 Vasek Pospisil

Andy Murray invested extra time this year in trying to crack Indian Wells, one of the only two Masters events he has yet to win. But the week of on-site training with coach Jamie Delgado failed to change his fortunes, as he suffered a straight-sets defeat in his opening match against world No. 129 Vasek Pospisil.

Statistically, this was Murray’s worst loss since 2011, when he went down to Donald Young at this same tournament. But it would be wrong to suggest that Pospisil is a duffer. Yes, he might have had to qualify for this event, but he also stood in the world’s top 40 as recently as 14 months ago, before suffering a form slump that he ascribes to personal issues.

Neither was this a real horror show from Murray, more a case of an inspired opponent who took the initiative and attacked him from the net in the manner reminiscent of Mischa Zverev’s equally surprising victory at the Australian Open seven weeks ago.

Even though Murray possesses an intimidating repertoire of lobs and passing shots, opponents are beginning to understand that you can disconcert the world No. 1 by coming forward, hitting a lot of volleys and knocking him out of his rhythm.

One upside is that Murray was only defending 45 points in Indian Wells after winning just a single match here last year. Indeed, he will extend his lead at the top of the rankings table if his leading rival Novak Djokovic fails to defend his title. And Djokovic has landed one of the toughest draws in living memory: in theory, Juan Martin del Potro, Nick Kyrgios, Roger Federer and Rafael Nadal are all lining up to face him before he even reaches the final.

Still, the puzzle of Indian Wells remains one that Murray has yet to crack, despite his own lone appearance in the final in 2009. The conditions in the desert near to Palm Springs are very particular. The air is thin, which means that the ball tends to fly during the heat of the day. Then it becomes much colder and heavier under the floodlights at night.

"I don't know exactly why it is,” said a non-plussed Murray when asked about his modest record at this tournament.

“In practice I normally play pretty well. I don't know if it's the conditions. I really don't know why I haven't played my best here over the years."

Murray wasted an early 3-1 lead to give up the first set 6-4, then went 6-2 behind in the second-set tie-break. When he saved three match points, narrowing the gap to 6-5, we wondered if we might be in for a reprise of his miraculous comeback against Philipp Kohlschreiber in Dubai ten days ago. But it was not to be, as Pospisil put away a sharply angled forehand winner on the next point.