Sergio Busquets probably felt like hiding behind his hands. “The ghosts appeared,” he said. It was a cold, dark night and everywhere he looked they were there. If he looked left, especially. Blue and white figures flew past. Over the other side, on the touchline, Ernesto Valverde pulled his jacket up tight and peered through the pouring rain. “You must have thought: ‘again’,” he was asked afterwards, when it was finally over – the match, the curse, probably the title, too. “Exactly,” he said. Everyone did. The day before, Barcelona’s manager had described this as the “worst place” – there was something about it that haunted Barcelona, had a hold over them, something that defeated them, or so it goes. Now, that seemed confirmed.

Between them, Pep Guardiola, Tito Vilanova, Tata Martino and Luis Enrique won six leagues, five Copa del Reys and three European Cups, 25 trophies in all, but not one league game at Anoeta. It had been more than a decade since Barcelona won there. Only Leo Messi and Andrés Iniesta were left from that day in May 2007, and Messi hadn’t appeared yet while Iniesta was sheltered on the bench – for his own protection, Valverde admitted, and for theirs, too. Except there was no protection from Real Sociedad, from Sergio Canales, Willian José, Xabi Prieto and Álvaro Odriozola, and Barcelona, unbeaten in 27, not defeated since the Super Copa was over and the season began, were losing.

Two-nil down, another one wrongly disallowed, it was happening again. The straight lines of a four-four-two with Paulinho and André Gomes wide were easily overcome and Jordi Alba was getting overrun. Willian José’s header raced in off the turf and Canales’s wonderful pass found Juanmi for the second. Here they were again; nowhere else had resisted for a decade, but Anoeta had. “You think of the past,” Busquets admitted. Then, suddenly, Luis Suárez was away down the left and Paulinho broke through the middle, and Barcelona scored. There were four minutes to go until half-time – and that’s Valverde time. Thirty-five of their 42 league goals have come in the second half; three of them came here.

An hour later, Valverde stood on the touchline wearing an incredulous look that said: “That guy.” Messi had just sent a high, looping free-kick into the net from 30 yards or more. Fifteen minutes before that Suárez had guided the ball in and 20 minutes before that he had taken the long way round the ball to send it in what one paper described as a “gothic arch” into the far corner, carefully curled into the far corner. Two-nil down, Barcelona were 4-2 up, another win secured, curse broken. As Messi’s shot looped into the net, la Real’s goalkeeper Geró Rulli stood and watched. There was nothing he could do.

There was nothing any of them could do. Not even la Real, not any more. On Monday morning, Marca’s front cover ran with: “No one can stop them.” At the halfway stage of the season Barcelona have 51 points. Only twice before have they ever had more – and this is the season that started, in Busquets’s words, with everyone thinking everything was going to go badly. They are unbeaten, and nine points clear at the top. “There’s a distance,” Valverde conceded. “We’re not ruling anyone out. The advantage of being first is that we only need to look at ourselves, and the numbers are what they are.”

For Real Madrid, the numbers are terrifying. If the weekend had been set up to be one last chance, something to cling on to, Anoeta offering a little hope, however fleeting, it didn’t turn out that way. Even before Barcelona confronted their ghosts it was over; they could have lost there and it wouldn’t have made a difference – to Real Madrid, anyway; Atlético, 1-0 winners at Eibar, might well be another matter.

Standing at the side of the Bernabéu pitch the day before, Nacho Fernández was asked if Madrid could still win the league. He squirmed a bit. “We would like to hope so,” he said but he knew they didn’t. A few minutes earlier, with the score at 0-0 against Villarreal, he had gone up for a corner. It was Madrid’s 12th and they sought a winner but it was Villarreal, like Betis before them, who got it. The ball dropped and they worked it into the path of Denis Cheryshev, racing up the right. His pass across found Enes Unal, one on one, and although Keylor Navas blocked the shot, Pablo Fornals floated the rebound over him and in.

Villarreal’s players raced to the corner, celebrating. It was the first time they had won at the Bernabéu, at the 19th attempt. “This tastes wonderful, we’re very happy; it’s historic,” Javier Calleja, the coach, said. “It’s madness in the dressing room,” Fornals added. Across the corridor, they could barely believe it. “Its not a fair result,” Zinedine Zidane insisted. “This is a hard; it’s a terrible blow. We did everything but the ball just didn’t want to go in. There’s no explanation.” The following morning AS ran on: “No goals, no luck, no explanation”.

Maybe there was something in that. Maybe. “Anyone who says we played badly has no idea about football,” Toni Kroos insisted. Madrid racked up 28 shots. Sergio Asenjo, returning from his fourth cruciate ligament tear, made seven saves. A couple of penalty claims were turned down, and Ronaldo hit the bar. It is a recurring theme: Madrid have had 348 shots, more than anyone else. Their expected goals total is 40.6; their actual total, excluding penalties and own goals, is 29. They’re averaging a goal a game fewer than last season, 2.78 to 1.77. Ronaldo, their top scorer with Gareth Bale and Marco Asensio has four, one for every 18 shots. 42 players have as many as he does.

Lionel Messi scores Barcelona’s fourth goal against Real Sociedad. Photograph: Juan Manuel Serrano Arce/Getty Images

The day before, Zidane said that he was annoyed that people said his team didn’t play well; on Saturday night, he said that it was “always the same question.” In part, that’s because it is so often the same story and so often the same answer. Unexplained is not the same as unexplainable. And luck is always a factor, yet it is rarely embraced when things go well. As the early games slipped through Madrid’s fingers, fortune, too, so a kind of fatalism took hold. They seemed to disengage.

The pegada that supposedly defined Madrid, that ability to deliver the knockout blow even when they’re not playing well, has deserted them. But if that was a quality then, its absence is a problem now. And to claim that their performances have been good would be a stretch. On Saturday they put in 38 crosses – which suggests maybe they deserved more but also that maybe they didn’t. There’s an apparent lack of fitness (their second half score reads 9-11) and belief, less contribution from the bench; maybe success sated them, too, maybe only Europe really matters, even if only subconsciously.

“Go look it up on Google,” Ronaldo said when his form was questioned, “the numbers don’t lie.” He was right of course, but the numbers are startling, too relentless to be overlooked or explained away as impossible to explain. The ball doesn’t want to go in but the ball doesn’t choose. Ronaldo’s European figures suggest there is indeed something a little freaky about his record in the league and as Valencia’s Marcelino put it this week, it’s true that “football’s a capricious son of a bitch sometimes”. Maybe it’s true, maybe the numbers don’t lie; they are what they are – very, very bad. At the halfway stage of the season, Madrid have already dropped more points than in the whole of last season. They have been beaten three times at home. They are 19 points behind Barcelona.

Nineteen.

Madrid have 11 points fewer than this stage last season and Saturday was the first time they had lost back-to-back league games at the Bernabéu in eight years. It is only the second time in their history they have been so far off the top. The Spanish, European and World champions are closer to the relegation zone than the top of the table. “We’d get killed if we were 19 points behind them,” Jordi Alba said. Real Madrid are also 10 points behind Atlético, eight points behind Valencia and only one point ahead of Villarreal. Sevilla are within a win of them. “Right now, our objective has to be to focus on qualifying for the Champions League,” Kroos said.

Talking Points

• The former Liverpool striker Iago Aspas has denied racially abusing Jefferson Lerma after the Levante midfielder accused him of calling him a “negro de mierda”, which roughly translates as “shitty black”. Lerma spoke to TV cameras after a match between Levante and Celta de Vigo on Sunday afternoon. “I would like to denounce [what happened],” he told BeIn Sport. “Aspas called me a negro de mierda. This can’t happen.”

Lerma, who said it was the first time it had happened to him, alleged that he told the referee but that the official did not want to know, saying that he was sick of his complaints. He expressed his hope that action would be taken and a statement from Levante expressed their support. Celta did not respond at first but a statement, quoting Aspas went for that horrible old favourite, which is demonstrably nonsense on just about every level: “What happens on the pitch stays on the pitch.” Aspas added: “I won’t say what he said to me but I did not call him what he says I did.”

• So Míchel’s gone and Quique hasn’t. Málaga blinked first: for a long time, they have wanted Míchel to jump while Míchel has wanted them to push him but the weeks went by, defeat by defeat, and no one moved. This week at last they did, when Malaga were beaten 1-0 at Getafe. As for Quique Sánchez Flores, he spent the week talking to Stoke, only to eventually announce that he was staying after all. Let’s never talk about it again, he sort of said after the match with Athletic. “We have a manager who wants to be here, and that’s all matters”

• Alavés are out of the relegation zone. A superb goal from captain Manu García gave them a massive 1-0 win over Sevilla.

• Harder To Run has left Barcelona, while Yerry Mina has arrived, barefooted.

• During Athletic Bilbao’s 1-1 draw at Espanyol, the goalkeeper Iago Herrerín hit the Spider Cam. Sadly, it was fine. Girona are a proper good team. Las Palmas are not. “It’s going to be a long night,” Paco Jémez said after his team were beaten 6-0 at Montilivi. “When you’re so pissed off and you feel so ashamed, things are hard. The players are gutted, there are people crying in the dressing room.”

• “I didn’t see the possible handball,” Eibar’s manager, José Luis Mendilibar, said, speaking for everyone. “But then I see lots of hands in a game and I don’t know when it’s a penalty and when it’s not.”