The Western Conference's third-seeded Golden State Warriors and Eastern Conference's second-seeded Boston Celtics meet in the NBA Finals. The Warriors and Celtics last met in a championship series in 1964, when Bill Russell registered the third of his seven playoff victories in eight tries against Wilt Chamberlain.

How they got here

Golden State Warriors (53-29)

The Warriors started the regular season 18-2 and resembled the pre-Kevin Durant version of Golden State's dynasty through November, two months before Klay Thompson returned from consecutive season-ending injuries and weeks into the careers of lottery draft picks Jonathan Kuminga and Moses Moody.

When Thompson returned in January, Draymond Green suffered a back injury, and when Green returned, Stephen Curry sprained his left foot. The three pillars of Golden State's six trips to the Finals played only 22 meaningful possessions together during the regular season. Their absences allowed Andrew Wiggins to earn his first All-Star appearance and Jordan Poole to emerge as a Most Improved Player candidate.

The lineup inconsistency led the Warriors to limp into the postseason with a sub-.500 record after the All-Star break, but they coalesced once Curry returned for the start of the playoffs. Their offensive firepower made quick work of the Denver Nuggets and Dallas Mavericks, who were respectively dependent on the singular greatness of Nikola Jokic in the first round and Luka Doncic in the Western Conference finals.

Golden State was tested only by the Memphis Grizzlies, who pushed the conference semifinals to six games despite losing All-NBA point guard Ja Morant to a right knee injury for half the series. The Warriors scored 113.5 points per 100 possessions — equivalent to a top-10 regular season offense — in their series against the Grizzlies and Mavericks, who owned the regular season's sixth- and seventh-rated defenses.

Offense has always been Golden State's calling card, but when the Warriors were winning championships, they played high-level defense, and they finished second in that regard over the course of the regular season (106.6 points allowed per 100 possessions). That figure has fallen to 111 in the playoffs, which would have ranked 13th during the regular season and is fifth among the last eight playoff teams standing.

Boston Celtics (51-31)

The Celtics owned an 18-21 record and placed 11th in the Eastern Conference after blowing a 25-point lead to the New York Knicks on Jan. 6. They were a .500 team during their 2020-21 campaign, and the chemistry between Jayson Tatum and Jaylen Brown was becoming sports talk-show fodder at the midway point of this season. Boston's two young stars met to affirm their commitment to playing with each other.

They responded, and the principles first-year head coach Ime Udoka had been emphasizing all season — passing up good shots for great ones on offense and switching everything defensively — fell into place. The Celtics' deadline trade for Derrick White extended the rotation to seven players who can move the ball on offense and stop it on defense. Over the final three months of the regular season, Boston posted the NBA's best defensive rating (104.9) by a wide margin and the league's second-best offensive rating (118.5).

Tatum made the All-NBA first team. Brown received votes for the third team. Marcus Smart won Defensive Player of the Year. Robert Williams III was the All-Defensive second team's center. Tatum, Brown and prodigal veteran Al Horford all earned All-Defensive votes. Holes in their rotation are few and far between.

Showing their collective growth, the Celtics swept Kevin Durant and Kyrie Irving's Brooklyn Nets in the first round. They rallied from a 3-2 deficit in the Eastern Conference semifinals to beat Giannis Antetokounmpo and the defending champion Milwaukee Bucks, who were without Khris Middleton, in seven games. And they beat Jimmy Butler's injury-plagued (but battle-ready) Miami Heat in another Game 7 on the road.

Facing three of the 12 best offenses during the regular season, Boston has allowed 105.1 points per 100 possessions in the playoffs, besting their league-leading regular-season defense by more than a point. The Celtics scored 110.7 points per 100 possessions over seven games against the Heat's vaunted defense.

Head to head

The Warriors and Celtics split their regular season series, 1-1.

Golden State won the first matchup in mid-December, 111-107, with rookie Moses Moody starting in the absence of both Thompson and Poole. Curry and Wiggins combined for 57 points on 41 shots. Likewise, Boston started Romeo Langford without Horford or Grant Williams in the lineup. Tatum and Brown combined for 47 points on 35 shots in a rotation that was still a work in progress before the trade deadline.

Boston won the second matchup in mid-March, 110-88. Curry suffered an ankle injury 20 minutes into the game, when Smart dove for a loose ball at his feet. The play struck a nerve with Warriors coach Steve Kerr, who called it "a dangerous play." Tatum and Brown combined for 52 points on 37 shots in the victory. Poole and Thompson scored a combined 47 points on 44 shots in defeat. The road team won both meetings.

In the limited two-game sample size that saw the winning team lead by 20 points each time:

• Golden State shot 94 3-pointers (28.7 3P%) to Boston's 86 (37 3P%). The Warriors created 83 open or wide-open 3-pointers and shot below 30% on them. The Celtics shot 38.9% on 72 open or wide-open 3s.

• Boston scored 12 points (4-5 FG) off Golden State's nine live-ball turnovers. The Warriors scored 12 points (4-14 FG) off the Celtics' 17 live-ball turnovers. Boston outscored Golden State in transition, 22-20.

• Boston held a slight advantage in rebounding percentage both defensively (75.2%-73.5%) and offensively (26.5%-24.8%), although Golden State still managed to edge the Celtics in second-chance points, 22-21.

• Boston shot 80.6% on 31 field-goal attempts at the rim and scored 78 points in the paint. Golden State shot 73.9% on 23 field-goal attempts in the restricted area and scored 64 points in the paint. The Celtics also generated 37 free-throw attempts from field-goal attempts inside the 3-point line to the Warriors' 20.

Closing lineups

Golden State Warriors

Warriors head coach Steve Kerr has relied heavily on Curry, Poole, Thompson, Wiggins and Green at the end of close games. That group is +17 in 30 fourth-quarter playoff minutes together. Payton earned some run with that unit when it needed more defense. Kevon Looney and Otto Porter Jr. are also available if Boston's size proves too difficult for Poole to handle on either end of the court. Gary Payton II (left elbow), Porter (left foot) and Andre Iguodala (neck) have all yet to scrimmage with Golden State since the end of the conference finals.

Boston Celtics

Udoka has primarily closed tight games with Smart, Brown, Tatum, Horford and an inconsistent Grant Williams. They have been outscored by eight in 47 fourth-quarter playoff minutes together. Boston has turned to White in place of Williams in a smaller version of that lineup more recently, and they are a more encouraging +25 in 31 fourth-quarter minutes as a quintet. Had Robert Williams not battled inflammation in his surgically repaired left knee throughout the playoffs, he also might have seen some clutch minutes.

Matchup to watch

This series will almost certainly come down to how well Golden State's offense performs against Boston's defense, so it stands to reason the matchup between the greatest shooter in NBA history and the league's reigning Defensive Player of the Year will go a long way toward determining the outcome of the Finals.

In the 45 minutes that Curry and Smart shared the floor together over two games during the regular season, Curry made only seven of his 21 field-goal attempts (5-15 3P) and committed 10 turnovers for a -15 rating. The two-time MVP finished 2 for 8 from the field and recorded a single assist against five turnovers in nearly seven minutes directly matched up against Smart. The Celtics are the only team with a winning record (9-7) against Kerr-era Warriors, largely due to their ability to counter Curry with exceptional perimeter defenders.

In the NBA's database of tracking statistics, Smart has defended Curry for 145 possessions over roughly 27 minutes since the start of the 2017-18 season, holding the Warriors superstar to 30 points on 11-for-30 shooting (6-20 3P) and three assists. Curry has drawn one foul from Smart and committed seven turnovers.

Like Smart, White possesses a 6-foot-8 wingspan and has also enjoyed some level of success defending the smaller Curry. Anything close to slowing Golden State's engine will give Boston a chance in the series.

Series schedule

Thursday: Boston at Golden State, 9 p.m. ET (ABC)

Sunday: Boston at Golden State, 8 p.m. ET (ABC)

June 8: Golden State at Boston, 9 p.m. ET (ABC)

June 10: Golden State at Boston, 9 p.m. ET (ABC)

June 13: Boston at Golden State, 9 p.m. ET (ABC)*

June 16: Golden State at Boston, 9 p.m. ET (ABC)*

June 19: Boston at Golden State, 8 p.m. ET (ABC)*

(*if necessary)

BetMGM series odds

Golden State Warriors (-160)

Boston Celtics (+130)

Prediction

The better rested and more experienced Warriors in seven.

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Ben Rohrbach is a staff writer for Yahoo Sports. Have a tip? Email him at rohrbach_ben@yahoo.com or follow him on Twitter! Follow @brohrbach