Madrids defending this year is a joke... much is being made of their misfiring attack, but jesus, some of their defending would make Arsenal defenders laugh.
Much has to be made of their attack, since 2009 which was Real worst recent year (Pre Florentino & Cristiano)
Real never failed to score more than 100 goals in a season for 8 straight years, they're on route to score ~70 goals right now, worse than that 2009 season they started with Schuster.
Real have been a ~1 goal conceded per game team for those same 8 seasons (bar Mourinho era, who lowered it a little), they're right now at 16 conceded in 17 games.
Defensively, their standard seems the same, I do believe that they were somehow better in the past, thanks to Pepe (who I regard highly) but stats prove otherwise, so I can't extend beyond a gut feeling right now, their attack is holding them down, right now Real Madrid are
1st in shots per game in La Liga (18.8) 3 more than the 2nd which is Barcelona
2nd in shots on target (6.9) 0.4 behind Barcelona
And we could think it's because they just shoot from distance and fail to get inside the area, but that's not true
Or the usual "well, that's because Ronaldo shoots a loot from outside the box", not anymore
Or the direct comparison between squads
End of the day Real and Barcelona show up in the enemy area around the same amount of time, but Ronaldo, Bale, Benzema and Asensio have failed to convert what Messi, Suarez and Paulinho do.
Mention to Isco too, who for all the amount of flak he gets from "slowing down the team" has the best conversion ratio in Real Madrid
And not only with Real Madrid, he's been on fire with Spain too lately, but somehow the idea of playing Isco as a false 9 has flown over Zidane's head for months, when it's something he did fairly good even in his debut with Real Madrid back in 2014. If a guy that's been in hot scoring form for almost 8 months doesn't get to play further in the pich with Zidane while Benzema gets minutes without converting and Ronaldo keeps shooting and shooting without success... then you can expect them to keep bleeding points until Ronaldo returns to scoring form or they sign the next hot thing.