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Toronto Raptors

One Play: Boston Celtics bring greatest Toronto Raptors concern to light in Game 1

Welcome to "One Play!" Throughout the 2019-20 NBA season, our NBA.com Staff will break down certain possessions from certain games and peel back the curtains to reveal its bigger meaning.

Today, the Boston Celtics and Toronto Raptors take the spotlight.

Context: I'm not sure Game 1 could've gone much worse for the Raptors.

Not only did they trail by as many as 24 points at one point, but they got off to a slow start, couldn't hit a shot from 3-point range all game long, got one of Pascal Siakam's worst games of the season, got one of Fred VanVleet's worst games of the season and didn't win the important battle of the second units.

Additionally, the Raptors weren't able to get out in transition against the Celtics, with the Celtics limiting them to seven fastbreak points despite committing 22 turnovers.

Of everything that went wrong for the Raptors in Game 1, them not being able to get out on the break might take the cake. We'll get into why in a bit, but first, let's take a close look at one particular play that illustrated how the Celtics made life difficult for the Raptors in the open court in Game 1.

The play: Siakam misses a shot over Semi Ojeleye in the post after a steal from VanVleet.

Breakdown: Let's start with the steal.

VanVleet, who averaged the third-most steals in the NBA this season and the most deflections, comes up with a steal on Jayson Tatum on the left wing. When he corrals the ball, VanVleet is almost at the same level as Tatum and Marcus Smart, who are Boston's only hope of stopping him from getting a quick basket in transition.

VanVleet generated a large portion of his offence on those plays on the season. According to NBA.com, he averaged 5.0 points per game in transition, the 15th-highest rate in the league behind players like Giannis Antetokounmpo, Russell Westbrook, LeBron James and Siakam. He was around league average in efficiency, ranking in the 48th percentile with 1.11 points per possession.

Knowing how much of a threat VanVleet is to score in transition, Tatum and Smart both put their heads down to sprint back on defence.

This, my friends, is effort:

Notice how there was a decent amount of space between Tatum and Smart at the start of the play and how they're now almost side-by-side? Tatum does an excellent job of funnelling VanVleet towards the middle of the court while Smart closes in to prevent him from getting a straight-live drive.

They've done their first job, which is to stop the ball.

Kyle Lowry isn't lagging far behind on the play, but Smart quickly switches onto him, leaving Tatum to guard VanVleet.

With no other option, VanVleet dribbles the ball out to the 3-point line to reset, by which point all five Celtics are in the frame compared to only three Raptors.

This is where the basketball genius of Smart comes into play.

Remember when Smart switched onto Lowry? He quickly sniffs out the biggest mismatch when Serge Ibaka and Marc Gasol arrive on offence: Brad Wanamaker, who stands at 6-foot-3 and 210-pounds, guarding Ibaka, who stands at 7-feet and 235-pounds.

Smart is only 6-foot-3 himself, but he has the strength at 220-pounds to hold his own against bigger players in the post. Based on data gathered by Krishna Varsu of The BBall Index, Smart spent 24.4 percent of his minutes guarding power forwards and centres this season, an incredible figure considering he has the height of a point guard. He guarded legitimate power forwards and centres as well, including Giannis Antetokounmpo and Kevin Love.

That's why Smart tells Wanamaker to switch onto Lowry - he's far more comfortable guarding a big like Ibaka than Wanamaker is.

Forced into their halfcourt offence, the Raptors look to Siakam in the post to get them a bucket.

Siakam is more than capable of scoring with his back to the basket - he ranked in the 50th percentile with 0.92 points per post-up possession this season - but the Celtics don't exactly make it easy on him.

Built like a brickhouse at 6-foot-6 and 240-pounds, Ojeleye makes Siakam fight for every inch while the rest of the Celtics lurk to make their presence felt.

Siakam gets a decent look, but on a night where he finished with 13 points on 5-for-16 shooting from the field, he's unable to get it to drop. The Celtics secure the rebound.

Why it matters: The Raptors probably won't miss as many 3s as they did in Game 1 again in these playoffs. They should also get much better performances out of Siakam, VanVleet, Ibaka and Norman Powell moving forward, the combination of which should make the rest of this series much much more competitive than Game 1 was.

As for getting easy baskets in transition? I'm skeptical.

As I wrote coming into the series, what makes the Celtics such a big threat to the Raptors is that they're one of the best teams in the league when it comes to limiting their opponents in transition. Now, the Raptors aren't just any opponent in that regard - no team scored more points in transition than Toronto this season and only two teams did so more efficiently - but this isn't the first time that the Celtics have been able to limit them in transition.

According to NBA.com, the Raptors scored less than 13 fastbreak points in only 19 games during the regular season. The Celtics were responsible for not one, not two, not three, but four of those games. While some of that had to do with Siakam, who averaged the fifth-most points per game in transition this season, missing two of those games with injury, Boston's ability to keep Toronto out of the open court was on full display when the two sides met at full strength in the seeding games.

The reason it matters is that the Raptors are a different team when the game slows down. According to Cleaning The Glass, they averaged 94.5 points per 100 possessions in the halfcourt, ranking them 16th among the league's 30 teams. (For comparison, the Celtics averaged 96.8 points per 100 possessions in the halfcourt, ranking them 11th).

That's not to say the Raptors are incapable of creating good looks for themselves in the halfcourt because they can. VanVleet has grown tremendously as a pick-and-roll scorer this season, Siakam continues to improve as a 1-on-1 scorer, Lowry is as crafty as they come, Ibaka and Gasol are among the best shooters at the centre position and Powell provides instant offence off the bench. The numbers just point to them being average in that regard, whereas the numbers point to them being the best team in the league in transition. It's where the Raptors miss Kawhi Leonard the most, as he's one of the best - if not the best - halfcourt scorers in the league right now.

It doesn't help that the Celtics are a tough team to score against in the halfcourt as well. They're without Gordon Hayward, who is one of their most versatile defenders, but Tatum, Smart and Jaylen Brown can defend at least three positions each, and Daniel Theis is more capable of defending the perimeter than you might think. There are very few times where teams can point to there being an obvious mismatch against the Celtics, made all the more difficult by them being a well-coached team that knows when to help and how to rotate.

The result? The Celtics gave up 91.6 points per 100 possessions in the halfcourt this season, the fourth-best rate in the league.

That's the recipe for beating these Raptors - keep them out of transition and force them into their halfcourt offence. It's much easier said than done, of course, but the Celtics are one of the few teams that have the personnel to do it. They proved it in their four regular-season meetings with the Raptors, then again in Game 1 of this second-round series.

The pressure is now on the Raptors to either figure out how to get out in transition against the Celtics or how to unlock their halfcourt offence.

The views on this page do not necessarily reflect the views of the NBA or its clubs.

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