To immediately understand the principal reason Betis humiliated Barcelona this weekend at the Camp Nou, you can go back to mid-July 2008 on a training pitch in St. Andrews, Scotland.
Yes, Ernesto Valverde was soundly beaten on tactics by Quique Setien.
Yes, if you compare Pau Lopez's superb first-half save from point-blank range, when Clement Lenglet thought he had scored, against Marc-Andre ter Stegen's limp-wristed effort that let Betis go 3-1 up, they can tell one tale of why the points went...
Barcelona's Sergio Busquets gives signed shirt to Betis coach Quique Setien, boss tipped for Camp Nou
After becoming the first coach to inflict a home defeat on Barcelona in 26 months, Real Betis manager Quique Setien's stock has never been higher.
With a reputation for prioritising attractive, attacking football, the word on the wire in Spain is that Setien may well end up plying his trade with Barca, and sooner rather than later.
Indeed, with Ernesto Valverde's future uncertain beyond the summer, there are some who believe the Catalans will make their move to bring the highly-regarded Betis boss...