The Portuguese coach settled on a lineup of Thibaut Courtois, Fede Valverde, Ibrahima Konaté, Dean Huijsen, Marc Cucurella, Aurélien Tchouaméni, Bernardo Silva, Arda Güler, Jude Bellingham, Yann Diomande and Kylian Mbappé.
That stability followed a run of 8 wins in 8 matches between the two international breaks.
According to the Spanish newspaper "Sport", the outlines of this lineup began to take shape during the Clásico, before Belgian goalkeeper Thibaut Courtois came in for Andriy Lunin.
A short injury list helped lock the side down, the fruit of solving a complex set of technical problems. Mourinho needed around 100 days of work and 16 matches to reach the current combination.
The midfield-pairing dilemma
Since taking charge of Real Madrid, Mourinho has insisted that no one stands above the club's badge, and that no player holds an untouchable place in the starting eleven.
Related Topics
He delivered that message when asked about Vinícius Júnior, who missed 4 La Liga matches through the suspension that followed his red card against Villarreal.
His absence coincided with Yann Diomande nailing down a place in the starting lineup, one of the elements that helped the Royal club find the right combination.
Fixture congestion across the various competitions is bound to force a few logical changes, yet through November these names appear to be Mourinho's preferred choice in the big fixtures.
The journey of experiments was a long one. After a summer window in which he held the authority to take part in decision-making, Mourinho leaned first on Bernardo Silva and Fede Valverde, then on the physical strength of Aurélien Tchouaméni and the Uruguayan, before shifting the latter back to full-back.
Nowhere did he tinker more than in the holding-midfield area. He used 7 different combinations and made 9 changes between matches.
For all the reshuffling, the pairing of Tchouaméni and Valverde remains the most used this season, despite the physical confrontation that set them against one another last term.
The two played together against Elche, Atlético Madrid, Villarreal and Roma. After the thrilling comeback Real Madrid pulled off in Italy, Mourinho decided to change his technical ideas.
Paradoxically, balance returned to the midfield when Bernardo Silva came back into the starting lineup. The Portuguese had started the season in the side before dropping out of the reckoning for a spell.
Silva played 3 matches alongside Valverde, against Espanyol, Real Sociedad and Rayo Vallecano, and lined up with Eduardo Camavinga in the Champions League against Germany's Leipzig and Greece's AEK Athens.
The pairing that has forced its way through of late, though, is Bernardo Silva and Tchouaméni. The pair started against Barcelona, Racing and Valencia.
Among the other combinations, Camavinga and Valverde started against Málaga and Real Betis, Trent Alexander-Arnold and Valverde against Inter Milan, and Arda Güler and Tchouaméni against Sevilla.
That last match marked the beginning of the shift towards the current lineup, with Mourinho returning Valverde to right-back after relying on him in midfield through the first ten matches.
6 different full-back pairings
Both full-back positions saw constant change over the first 16 matches. Mourinho used 6 different pairings and made 13 changes between matches, the highest number of any line in the team.
Remarkable, given these are two positions Real Madrid were keen to reinforce across the past two summer windows.
New arrivals Denzel Dumfries and Marc Cucurella formed the most-used pairing, starting 5 matches together against Real Betis, Inter Milan, Atlético Madrid, Roma and AEK Athens.
Ironically, the pair started in the only two defeats the Royal club have suffered so far, against Inter Milan and Atlético Madrid.
Three further pairings each recurred in 3 matches: Dumfries and Álvaro Carreras against Espanyol, Real Sociedad and Rayo Vallecano, Trent Alexander-Arnold and Cucurella against Málaga, Elche and Racing, and Valverde and Cucurella against Sevilla, Barcelona and Valencia.
That last pairing is the most settled now, having forced its way into the starting lineup.
By contrast, Trent Alexander-Arnold and Álvaro Carreras started just once, against Villarreal, while Valverde and Carreras played the Leipzig match.
Centre-back also saw Mourinho's choices evolve, one of the positions Real Madrid have spent heavily to reinforce in recent years.
He used 4 different pairings in central defence and made 10 changes between matches.
On performance, physical condition and harmony, Dean Huijsen and Ibrahima Konaté were the first choice. The pair played together in 10 of the 16 matches, against Espanyol, Real Sociedad, Real Betis, Inter Milan, Elche, Atlético Madrid, Sevilla, Barcelona, Racing and Valencia.
Antonio Rüdiger featured in the three other combinations, partnering Konaté 3 times against Rayo Vallecano, Villarreal and Roma, and Huijsen twice against Málaga and Leipzig.
He also played once alongside Éder Militão, recently returned from injury, against AEK Athens, and his level may hand the team extra options at the back.
5 attacking combinations led by Mbappé
The front line was no different. Mourinho tested several attacking combinations, factoring in the players' names and their standing within the team.
Kylian Mbappé is the only player to have started all 16 matches, while Jude Bellingham started 15, missing out only against Elche, when Arda Güler took the advanced playmaker role.
Five different attacking trios came and went, with 12 changes between matches.
Arda Güler, Mbappé and Vinícius Júnior remain the most-used trio, featuring in 5 matches against Espanyol, Real Sociedad, Real Betis, Atlético Madrid and Leipzig.
One match behind comes Yann Diomande, Arda Güler and Mbappé, a trio used in 4 matches against Villarreal, Barcelona, Racing and Valencia before Mourinho settled on it of late.
Diomande, Mbappé and Vinícius Júnior also started 4 matches, an attempt to strike a balance between the various attacking elements, against Rayo Vallecano, Elche, Roma and AEK Athens.
Mourinho turned to Brahim Díaz, Mbappé and Vinícius Júnior in two matches against Málaga and Inter Milan, while the Sevilla fixture, the turning point towards the current lineup, saw Diomande, Endrick and Mbappé lead the line.
Arda Güler is the common thread in most of the attacking combinations. He started 9 times within the attacking trios, once as the advanced playmaker, and once more within the holding-midfield pairing.
The Turk's flexibility, together with Valverde's versatility across multiple roles, let Mourinho change the team's style without having to change every name in the lineup.
So he built his side gradually over 16 matches, arriving at last at a combination that is now clearly defined and easily recognisable.
