Real Madrid have higher xG than Barcelona and have scored more goals too. Real Madrid also have higher xGD than Barcelona. So as far as those go, Barcelona do not have better 'underlying numbers.'
Mh, you're right, the numbers are pretty much the same now. +0.64/+0.66 xGD. So real madrid have caught up in that. Big chances are also more or less the same, in fact pretty much every metric i'm seeing right now is.
We're 17 points clear of them
Real Madrid have higher xGA than Barcelona while conceding less goals. That's mildly interesting
What's more interesting is the Post-Shot numbers. Real Madrid go from 23.3 xGA to 18.9 PSxGA(tied for 4th best) with a PSxGA per SoT of 0.24(2nd best in the league). Conceded 18
Barcelona go from 19.2 xGA(league 3rd best) to 20.9 PS(8th) with 0.35 per SoT which is the worst figure in the league. Conceded 23
I don't have access to data to tell whether these numbers are down to variance or something to do with how the teams defend that the model doesn't capture yet, but i'd lean with the second wrt us from watching our games. We're really good at putting pressure on shots/closing down angles
PS: bonus, funniest stat in the league this season: Jan Oblak, worst goalkeeper in the league and one of the very worst in europe's top 5 leagues
might be single-handedly dragging atleti down in fact, their defensive numbers are otherwise still robust