Biggest X-Factors for Boston Celtics vs. Golden State Warriors in NBA Finals

It's unusual for an NBA Finals matchup to feature as much mystery as the one that'll kick off on Thursday when the Boston Celtics take on the Golden State Warriors.

These two teams squared off only twice during the regular season, and key absences left both meetings short on predictive value.

In the Warriors' 111-107 victory in Boston on Dec. 17, the Celtics were without five players due to health and safety protocols, including rotation fixtures Al Horford and Grant Williams. They also didn't have Derrick White, who wouldn't arrive until the trade deadline.

On the Warriors' end, Klay Thompson had yet to return from his two-year absence.

The second engagement, a 110-88 Celtics win, came on March 16. Boston was whole, but the Warriors were without Andrew Wiggins, while Draymond Green didn't start and was limited to 22 minutes in his second game back after over two months on the shelf. Most critically, Stephen Curry exited after logging just under 14 minutes. That was the night Marcus Smart dove for a loose ball and rolled up Curry's left foot, an injury that kept the two-time MVP on ice until the playoffs.

The only thing those games revealed was the importance of health. But that's hardly a revelation. And you also don't need a genius to tell you the stars and starters need to play well for their teams to win. Those are basics, not X-factors.

Here, we'll look deeper to find specific players and strategic pivot points that will determine this year's NBA champion.

This series features the top two defenses in the league, which means the team that wins it will almost certainly be the one that figures out how to score.

The Warriors will dare Boston's suspect perimeter shooters, Marcus Smart and Derrick White, to be the determining factors.

Against the Memphis Grizzlies, Golden State sagged off Ja Morant and Kyle Anderson, and it practically begged Dillon Brooks to win games from deep. In the next round, the Warriors gave Frank Ntilikina and Josh Green acres of open space. These were calculated gambles designed to shift defensive focus to the paint while betting that inviting less dangerous threats to shoot would siphon touches away from better scorers.

The Warriors have been doing this since they swung a 2015 postseason series against the Grizzlies by ignoring Tony Allen. It's kind of their thing.

Smart has a history of taking the bait, and his trigger-happy play down the stretch of Game 7 against the Miami Heat nearly produced an epic playoff choke job. His 33.1 percent clip from long distance ranked 71st among the 79 players who attempted at least 360 triples during the season. White was even worse, ranking 78th out of those 79 high-volume shooters with a paltry 31.2 percent hit rate. 

White's best series from a shooting perspective came against the Heat, when he made only 33.3 percent of his treys. He was a combined 9-of-37 (24.3 percent) across the first two rounds. He'll be left wide open every night.

If Smart can shoot 39.4 percent on threes like he did in the second round against the Milwaukee Bucks, the Celtics will be in business. If he repeats his 28.9 percent performance from the Miami series, Golden State will have a huge advantage.

Both guards are vital to the Celtics defense, so head coach Ime Udoka won't take them off the floor if they're cold from beyond the arc.

It's a cop-out to use the old "make-or-miss league" refrain when searching for X-factors. But these two Boston guards are uniquely positioned to either supercharge or derail their team's offense.

The Warriors have the highest offensive rating in these playoffs, and their half-court scoring rate ranks third among all postseason teams. But where they've really excelled is in finding extra buckets on the margins—on the offensive glass, in particular.

Among teams that reached the conference finals, Golden State's 14.5 second-chance points per game ranks first. Kevon Looney and Andrew Wiggins are tied for the postseason lead with 42 offensive boards apiece, and when you adjust for playing time (Looney has logged 318 minutes to Wiggins' iron-man 531), Golden State's 6'9" center is clearly the postseason's most impactful board-hoarder.

Though glasswork is typically thankless, Looney's rebounding has been impossible to ignore. His efforts have produced dagger threes and MVP chants. His 22 total rebounds (11 offensive) in the series clincher against Memphis were vital, and Looney came up big again as the Warriors eliminated Dallas. He inhaled 18 boards in a decisive Game 5, including seven on offense.

Against a Celtics team that will have significantly more size at every position, Looney's performance on the boards will be critical.

If he can secure handful of extra possessions and chip in a few easy putback buckets, it'll go a long way toward helping the Warriors eke out points against the otherwise unforgiving Celtics defense.

We said we'd stay away from the obvious health and injury concerns because there's nothing novel about saying both teams will be better off if their rotation players are healthy. Golden State will benefit if Gary Payton II, Otto Porter Jr. and Andre Iguodala are available (which is still in doubt), and Boston would certainly be more dangerous if Marcus Smart's various bumps and bruises have time to heal.

But there's one specific health-related concern worth special attention: Robert Williams III's surgically repaired right knee.

A torn meniscus knocked Williams out of action in late March, but he missed less than a month from the date of his operation. He's since looked intermittently hobbled and has (understandably) missed games due to soreness in all three series that the Celtics have played.

Boston was the league's second-best team with respect to limiting opponent shot frequency at the rim, and Williams improved its efforts in that area whenever he was on the floor. That's to say nothing of the transformative impact he had after the Celtics decided to build their defense around his ability to cover corner shooters and still recover to the lane to block or alter shots.

The Warriors feasted in the lane during the conference finals against a Dallas team lacking rim protection. Golden State averaged 49.2 points per game in the paint against the Mavericks, a number that would have tied the Memphis Grizzlies for the league lead in that statistic during the regular season.

If Williams is mobile enough to stick to his corner assignment and still get into the lane as a deterrent, the Warriors could lose one of the prime scoring avenues that sustained them against the Mavs. But if Williams isn't up to the tough task of helping and recovering against an offense that specializes in tying big men in knots, the Celtics could find themselves surrendering layups and kickout threes at high volume.

Among Warriors players averaging at least one isolation possession per game in these playoffs, Jordan Poole has the runaway lead in efficiency. That's no surprise if you've ever seen the 6'4" guard slither through a defense or roast his man with a wicked combination of long strides, short bursts, hesitations and barely-legal ball-handling.

Because the Celtics are the postseason's switchiest defense, and because they'll likely lean even harder into that tendency to negate Golden State's off-ball movement and screen game, isolation scoring could become a much larger share of the Warriors' offense than usual.

That will only increase Poole's already outsized importance as a something-from-nothing generator of offense.

Poole will actually be an X-factor in multiple senses during the Finals. His individual playmaking is vital to sustaining the Warriors' attack, especially when Stephen Curry is off the floor. At the same time, Poole has been just as big of a key to the opponent's offense.

In every series, he's been a target on defense. The Mavericks hunted switches to attack him relentlessly, just as the Grizzlies did in the previous round.

Though his 1.35 points per isolation possession in the playoffs are elite, ranking in the 97th percentile, his defense in the same situations has stood out for the opposite reason. He's allowing 1.24 points per play as an iso defender, which put him in the 17th percentile.

Poole will be the central figure in one of this series' most intriguing push-and-pull strategic battles. The Warriors will need his offense to counter Boston's switching schemes, but they'll also have to find ways to hide him defensively.

Winning the turnover battle is another cliche key we'll avoid. The Celtics and Warriors are both sloppy with the ball, ranking 13th and 14th in turnover rate during the postseason, respectively. Carelessness could swing this series, but that'd be the case with any two teams.

We need to put a finer point on it.

Jayson Tatum and Jaylen Brown are averaging 5.2 and 3.9 turnovers per 100 possessions, respectively, in the playoffs. Tatum's number is way up from the 3.9 giveaways per 100 possessions he posted during the year, while Brown has sustained exactly the same (poor) rate.

The turnovers are a problem in a vacuum, but they're more damaging because of what they indicate is happening to Boston's offense.

The Celtics are best when the ball is moving. When things stall out and the stars try to do too much, trouble ensues. Brown had some brutal stretches against Miami where it appeared as though he forgot how to dribble, and he then compounded the problem by barreling into thickets of sticky-fingered defenders.

The ripple effects of Boston's stars losing the rock are profound. Turnovers will allow the Warriors to attack in transition against a scrambled opponent. Golden State will rejoice any time it gets to avoid the slog of trying to score against a set Boston defense. And if Tatum and Brown are giving the ball away because they're forcing the issue on offense, Golden State likely will have found a way to curb player and ball movement.

You could flip this and argue Golden State's turnover issues could be even more dispositive, as Boston's offense might need the boost of more steals and breakaways than the Warriors'. But Tatum and Brown's issues taking care of the ball throughout these playoffs mean the spotlight has to be on them.

Stats courtesy of NBA.com, Basketball Reference and Cleaning the Glass. Accurate through 2021-22 season. Salary info via Spotrac.