2018 ATP Finals

The 2018 ATP Finals (also known as the 2018 Nitto ATP Finals for sponsorship reasons) was a men's tennis tournament that took place at the O₂ Arena in London, United Kingdom, from 11 to 18 November 2018. It was the season-ending event for the highest-ranked singles players and doubles teams on the 2018 ATP World Tour.

Champions

Singles

Alexander Zverev def. Novak Djokovic, 6–4, 6–3
* It was Zverev's 4th title of the year and 10th of his career. It was his first win at the event.

Doubles

Mike Bryan / Jack Sock def. Pierre-Hugues Herbert / Nicolas Mahut, 5–7, 6–1, 3–11ref name="doubles title"/>

Tournament

The 2018 ATP Finals took place from 11 to 18 November at the O₂ Arena in London, United Kingdom. It was the 49th edition of the tournament (44th in doubles). The tournament was run by the Association of Tennis Professionals (ATP) and was part of the 2018 ATP World Tour. The event took on indoor hard courts. It served as the season-ending championships for players on the ATP Tour.
The eight players who qualified for the event were split into two groups of four. During this stage, players competed in a round-robin format (meaning players played against all the other players in their group).
The two players with the best results in each group progressed to the semifinals, where the winners of a group faced the runners-up of the other group. This stage, however, was a knock-out stage. The doubles competition used the same format.

Points and prize money

Ref:
*RR is points or prize money won in the round robin stage.
*¹ Prize money for doubles is per team.
*An undefeated champion would earn the maximum 1,500 points, and $2,712,000 in singles or $517,000 in doubles.

Qualification

Singles

Eight players compete at the tournament, with two named alternates. Players receive places in the following order of precedence:
# First, the top 7 players in the ATP Race to London on the Monday after the final tournament of the ATP World Tour, that is, after the 2018 Paris Masters.
# Second, up to two 2018 Grand Slam tournament winners ranked anywhere 8th-20th, in ranking order
# Third, the eighth ranked player in the ATP rankings
In the event of this totaling more than 8 players, those lower down in the selection order become the alternates. If further alternates are needed, these players are selected by the ATP.

Provisional rankings are published weekly as the ''ATP Race to London'', coinciding with the 52-week rolling ATP rankings on the date of selection. Points are accumulated in Grand Slam, ATP World Tour, ATP Challenger Tour and ITF Futures tournaments from the 52 weeks prior to the selection date, with points from the previous years Tour Finals excluded. Players accrue points across 18 tournaments, usually made up of:

* The 4 Grand Slam tournaments
* The 8 mandatory ATP Masters tournaments
* The best results from any 6 other tournaments that carry ranking points

All players must include the ranking points for mandatory Masters tournaments for which they are on the original acceptance list and for all Grand Slams for which they would be eligible, even if they do not compete (in which case they receive zero points). Furthermore, players who finished 2016 in the world's top 30 are ''commitment players'' who must (if not injured) include points for the 8 mandatory Masters tournament regardless of whether they enter, and who must compete in at least 4 ATP 500 tournaments (though the Monte Carlo Masters may count to this total), of which one must take place after the US Open. Zero point scores may also be taken from withdrawals by non-injured players from ATP 500 tournaments according to certain other conditions outlined by the ATP. Beyond these rules, however, a player may substitute his next best tournament result for missed Masters and Grand Slam tournaments.

Players may have their ATP World Tour Masters 1000 commitment reduced by one tournament, by reaching each of the following milestones:
# 600 tour level matches (as of January 1, 2018), including matches from Challengers and Futures played before year 2011;
# 12 years of service;
# 31 years of age (as of January 1, 2018).
If a player satisfies all three of these conditions, their mandatory ATP World Tour Masters 1000 commitment is dropped entirely. Players must be in good standing as defined by the ATP as to avail of the reduced commitment.

Doubles

Eight teams compete at the tournament, with one named alternates. The eight competing teams receive places according to the same order of precedence as in Singles. The named alternate will be offered first to any unaccepted teams in the selection order, then to the highest ranked unaccepted team, and then to a team selected by the ATP. Points are accumulated in the same competitions as for the Singles tournament. However, for Doubles teams there are no commitment tournaments, so teams are ranked according to their 18 highest points scoring results from any tournaments.

Qualified players

Singles

On August 11, Rafael Nadal became the first qualifier to the event.

Rafael Nadal formally began his season at the Australian Open, Nadal faced Marin Čilić in the quarterfinal, but retired in the fifth set due to a hip injury. Nadal withdrew from the Mexican Open, Indian Wells Masters, and Miami Open due to an injury. At the Monte Carlo Masters, Nadal successfully defended his title, won a record-breaking 31st Masters title and his 11th title in Monte Carlo, beating Kei Nishikori in the final. Nadal went on to win his 11th title in Barcelona Open