[14][15][18] He was named the team's captain in 1985 under new club manager Sven-Göran Eriksson, and served as a mentor to the young midfielder Giuseppe Giannini, as Roma won the Coppa Italia, but once again narrowly missed out on the league title during the 1985–86 Serie A season, finishing in second place behind Juventus.

[14] During this time, Milan, under the financial backing of club president Silvio Berlusconi, featured players such as Paolo Maldini, Franco Baresi, Mauro Tassotti and Alessandro Costacurta as defenders; Frank Rijkaard, Ruud Gullit and Roberto Donadoni as midfielders; and Marco van Basten upfront.

[20] The following season, Ancelotti suffered an injury to his left knee in the quarter-finals of the European Cup against KV Mechelen, which forced him to miss the semi-finals, although he was able to return in time to help Milan defend their title against Benfica in the final, held in Vienna.

[14][15][17] Under manager Enzo Bearzot, Ancelotti made his Italy national team debut and scored his first and only goal on 6 January 1981 in the 1980 World Champions' Gold Cup against the Netherlands, which ended in a 1–1 draw.

[15] Ancelotti later went on to play in the 1990 World Cup on home soil under Vicini at the age of 31, although an injury in the first group match against Austria once again limited his appearances in the competition to just three, and kept him on the sidelines until the third-place final against England, in which he returned to help Italy to a 2–1 win.

[14][15][16] Although he lacked pace and physicality, he was a talented, hardworking, and tenacious player who had excellent technical ability, tactical intelligence, vision, and passing range; his most notable skill being his powerful and accurate shooting from outside the box.

[15][22][17][23][24][25] Ancelotti undertook his coaching studies at Coverciano, where he penned a research article entitled "Il Futuro del Calcio: Più Dinamicità"[26] (English: "The Future of Football: More Dynamism").

[32] With the new attacking partnership of Enrico Chiesa and Hernán Crespo, Parma finished second in Serie A during the 1996–97 season under Ancelotti, which guaranteed them a place in the next edition of the UEFA Champions League.

[42] Ancelotti's first full season at Juventus began promisingly, as he immediately won the Intertoto Cup with the club by beating Rennes 4–2 on aggregate,[43] although Juventus suffered a round of 16 elimination in the UEFA Cup, and lost the league title to Lazio by a single point on the final match-day of the season; this was after surrendering a five-point lead with three games remaining, which drew strong criticism from the board of directors.

[49] The following season, Ancelotti – who was heavily criticised by club owner Silvio Berlusconi due to his supposedly defensive tactics – was able to adopt a creative play in Milan while making several changes to the team's squad.

[70] After the departure of striker Andriy Shevchenko at the beginning of the 2006–07 season, Ancelotti was forced to redesign Milan's line-up once again, devising a 4–3–2–1 system that would later be known as his "Christmas Tree" formation.

[71] Milan received an eight-point deduction during the 2006–07 Serie A season for their role in the Calciopoli scandal,[72] which virtually put the team out of the title race, and instead led Ancelotti to focus on winning the Champions League.

First with a 7–0 thrashing of Ipswich Town in the FA Cup at Stamford Bridge, and then a 2–0 victory over Blackburn, followed by emphatic away wins against Bolton Wanderers and Sunderland, putting them in fourth position in the league, though still ten points behind leaders Manchester United.

[110] During Ancelotti's first full season at the club, PSG entered the winter break at the top of the Ligue 1 table, ahead of Lyon and Marseille on goal difference.

[120] On 16 April 2014, Ancelotti won his first major trophy as Real Madrid manager after they defeated Barcelona 2–1 in the Copa del Rey final held at the Mestalla Stadium.

[125] On 12 August, Ancelotti started the new season by winning another European trophy, leading Real Madrid to a 2–0 victory over Sevilla in the 2014 UEFA Super Cup.

In the last four months of 2014, his team set a Spanish record of 22 consecutive victories in all competitions that began on 16 September and culminated with Real Madrid's first FIFA Club World Cup title in December 2014, finishing the year with four trophies.

[130] They were eliminated in the round of 16 of the Copa del Rey by Atlético Madrid, whom they faced eight times throughout the season (including the UCL quarter-finals),[131] and lost 3–2 on aggregate to Juventus in the Champions League semi-finals.

[137] On 20 December 2015, Bayern Munich CEO Karl-Heinz Rummenigge confirmed that Ancelotti would replace Pep Guardiola as manager for the 2016–17 season, signing a three-year contract.

[162] Napoli eventually finished the 2018–19 Serie A season in second place, twelve points behind champions Juventus,[163] and reached the quarter-finals of the Europa League, losing out to Arsenal.

[168] On 1 March 2020, Ancelotti was sent off after the full-time whistle, following an on-pitch conversation with the referee Chris Kavanagh, who had ruled out a would-be late match-winning goal against Manchester United, due to an offside that was determined by VAR.

[171] During the close-season, Ancelotti signed his former players James Rodríguez and Allan, along with Ben Godfrey, Abdoulaye Doucouré, Niels Nkounkou and loanee Robin Olsen.

[174] After a drop in form, a resumption of good results saw Everton end 2020 in fourth place, but knocked out of the EFL Cup, losing 2–0 to Manchester United in the quarter-final.

[202] On 29 December, although he had previously been linked with the position of head coach for the Brazil national football team, Real Madrid announced that Ancelotti had agreed to a contract extension until 30 June 2026.

[213] Two months later, on 14 August, he achieved his record fifth UEFA Super Cup trophy with a 2–0 victory over Atalanta,[214] becoming the joint most decorated coach in the club's history along with Miguel Muñoz with 14 titles.

[216] Toward the beginning of his coaching career, and during his time with Parma, Ancelotti preferred to use a rigorous 4–4–2 formation, which made use of heavy pressing, and drew influence from that of his Milan and Italy coach Arrigo Sacchi, and which he believed to be the most successful system for his team; however, this system did not allow for more creative forwards, such as Gianfranco Zola, Hristo Stoichkov and Roberto Baggio, to play in their preferred positions, and ultimately led to Zola and Stoichkov's departure from the club, while Baggio's transfer to Parma in 1997 was impeded by Ancelotti.

[17][51][52][53][54][218][219][224][225][226][227][228][229][230][excessive citations] After the departure of one of the club's main strikers at the beginning of the 2006–07 season, Andriy Shevchenko, Ancelotti redesigned Milan's line-up, devising a 4–3–2–1 system, later known as his "Christmas Tree" formation.

[17][71] Moving to Chelsea, in the 2009–10 season Ancelotti continued with the 4–4–2 diamond formation used previously at Milan, often with Michael Essien or Mikel John Obi in the defensive role, Michael Ballack or Frank Lampard as box to box midfielders and Deco in a creative role, with full-backs Ashley Cole and José Bosingwa pushing forward and providing width to the narrow midfield.

He said that against Roberto De Zerbi's Shakhtar Donetsk, en route to his last Champions League title, he instructed his players not to press them, so that they would not play through the team.

Jude Bellingham served as a goalscoring attacking midfielder, with additional creative and defensive responsibilities, acting almost as a false-9 or second striker at times, and playing behind Vinícius and Rodrygo – normally wingers – upfront in free roles.