One Team, One Stat Boston Celtics 3 point Defense

http://www.nba.com/article/2018/09/25/one-team-one-stat-boston-celtics-3-point-defense

NBA.com's John Schuhmann gets you ready for the 2018-19 season with a key stat for each team in the league and shows you why it matters. Today, we look at the Boston Celtics, who have a remarkable history of defending the 3-point line.

THE STAT
The Celtics have ranked in the top five in opponent 3-point percentage in each of the last 11 seasons.

Celtics opponent 3-point shooting, last 11 seasons

THE CONTEXT
That's an incredible streak for a few reasons...

There's some noise (randomness) in opponent 3-point percentage. A defense controls it less than opponent field goal percentage inside the arc.
115 different people have played for the Celtics over that stretch. They've had some stability on the bench (just two different coaches over the 11 years), but the streak includes a team that went 25-57.
NBA offense has changed quite a bit over those 11 seasons, with the percentage of league-wide shots coming from 3-point range rising from 22 percent 2007-08 to 34 percent last season.
Over those 11 seasons, no other team has ranked in the top five in opponent 3-point percentage more than *five times. There are seven franchises that haven't once ranked in the top five since '07-08. Another 12 teams have ranked in the top five just once over those 11 years.

* The team that has ranked in the top five five times over the last 11 teams is the Chicago Bulls, with four of those five top-five finishes coming under Tom Thibodeau, who was the architect of the Celtics' defense at the start of their streak.

So that's 19 of the league's 30 teams that have ranked in the top five in opponent 3-point percentage no more than once in the last 11 seasons. The Celtics have done it in all 11. And last season, the Celtics led the league in opponent 3-point percentage for the third time in that stretch (and for the first time in Brad Stevens' five seasons).


According to Second Spectrum tracking, the percentage of their opponents' 3-point attempts that were contested was right around the league average. So was the percentage of their opponents' 3-point attempts that were off the catch (vs. off the dribble).


Are the Celtics the favorites in the East in 2018-19?
But the Celtics allowed opponents to take only 19 percent of their 3-point attempts, the lowest rate in the league, from the corners. As a whole, the league shot 35.6 percent on above-the-break threes and 39.3 percent on corner threes last season.

Celtics opponents actually shot almost 42 percent from the corners. But reducing the number of attempts that come from the corners is to better defend the 3-point line as a whole. And the 32.5 percent their opponents shot on above-the-break threes was the league's lowest mark.

Lowest percentage of opponent 3-point attempts from the corners, 2017-18

The Celtics' ability to switch screens allowed them to stay in front of ball-handlers and stay at home on shooters, but their opponents' 3-point percentage was actually lowest (31.6 percent) with Aron Baynes - one guy they didn't switch with as much - on the floor. Not coincidentally, the Celtics allowed just 97.0 points per 100 possessions with Baynes on the floor, and that was the lowest on-court DefRtg among players who averaged at least 15 minutes in 40 or more games.

With the league continuing to take more threes every year, the correlation between opponent 3-point percentage and defensive efficiency on a team-by-team level only gets stronger. And with their size, scheme and smarts, the Celtics should again be a top-five team in regard to both.

Celtics last five seasons

Note: The above table is based on true possession counts. Other efficiency stats here are based on possession estimates (typically higher than true possession counts).

CELTICS LINKS
History: Season by season results | Advanced stats | Franchise leaders
2017-18: Team stats | Advanced splits | Player stats | Player shooting | Lineups

CELTICS NOTES - GENERAL
Only team that has seen an increase in winning percentage each of the last four seasons, going from 25-57 in 2013-14 to 55-27 last season.
One of two teams - Phoenix (11, 10) was the other - with more road wins (28) than home wins (27) in the regular season. Then went 10-1 at home and 1-7 on the road in the playoffs.
At 22-8, had the best record among Eastern Conference teams against the Western Conference. Were one of two East teams (Detroit was the other) that beat both Golden State and Houston.
Were 29-1 after leading by at least 15 points. Only Portland (33-1) had a better record when up by 15-plus.
Tied for the league lead with 15 wins (they were 15-20) after trailing by double-digits.
In the playoffs, they were outscored by 27 in the first half of games, but were a plus-31 in the second half.
Celtics shooting stats

CELTICS NOTES - OFFENSE
Saw the league's third biggest drop in OffRtg, from 108.6 points scored per 100 possessions (eighth in the league) in 2016-17 to 105.2 (18th) last season.
Ranked second in 3-point percentage (37.7 percent) and first in pull-up 3-point percentage (36.4 percent). Were one of two teams with two players (Al Horford and Jayson Tatum) in the top 10 in 3-point percentage among individuals (and the other pair is no longer on the same team). But they saw the league's biggest drop in the percentage of their shots that came from 3-point range, from 39 percent (third highest rate in the league) in 2016-17 to 36 percent (eighth) last season.
Saw the league's second biggest drop in assist percentage, recording assists on 58.6 percent of their field goals (13th in the league), down from 65.3 percent (second) in 2016-17.
Ranked 24th in player movement (distance traveled per 24 minutes of possession) and 19th in ball movement (passes per 24 minutes of possession).
Celtics four factors

CELTICS NOTES - DEFENSE
Have been a better-than-average defensive team in 10 of the last 11 seasons.
Ranked sixth in opponent field goal percentage in the paint (53.5 percent) and first in effective field goal percentage on shots from outside the paint (45.8 percent).
Opponents had an effective field goal percentage of just 39.6 percent, the league's lowest mark, in the last six seconds of the shot clock, according to Second Spectrum tracking.
Opposing pick-and-roll ball-handlers had an effective field goal percentage of 41.7 percent, the league's lowest opponent mark, according to Synergy tracking.
CELTICS NOTES - LINEUPS
The Celtics are returning their 15 most-used lineups from last season. A year ago, they only returned four players (and, therefore, zero lineups) from the season prior.
Most-used starting lineup (35 games) - Irving, Brown, Tatum, Horford and Baynes - outscored its opponents by 13.4 points per 100 possessions, the fourth best mark among 29 lineups that played at least 300 minutes together. Second most-used starting lineup (10 games) - Irving, Brown, Tatum, Morris and Horford - was outscored by 9.7 points per 100 possessions in its 148 total minutes.
Allowed 93.7 points per 100 possessions with Baynes, Brown and Horford on the floor. That was the second lowest on-court DefRtg among the league's 250 most-used three-man combinations. Allowed 96.7 points per 100 possessions with Baynes and Tatum on the floor. That was the second lowest on-court DefRtg among the league's 250 most-used two-man combinations.
In the playoffs, lineup of Rozier, Smart, Tatum, Morris and Horford outscored its opponents by 25.0 points per 100 possessions, the second best mark among 25 lineups that played at least 50 postseason minutes.
The Celtics were almost 14 points per 100 possessions better with Al Horford on the floor (plus-4.2) than they were with him on the bench (minus-9.7) in the playoffs.
CELTICS NOTES - INDIVIDUAL
Aron Baynes made almost three times as many 3-pointers in 2018 playoffs (11) as he's made in his 376-game, regular-season career (4).
Jaylen Brown took 39 percent of his 3-pointers from the corners, the fourth highest rate among 150 players with at least 200 total 3-point attempts.
Brown averaged 30.7 minutes per game last season, up from 17.2 as a rookie. That was the biggest increase among 260 players who played in at least 40 games both seasons. He also saw the fourth biggest increase in points per game (from 6.6 to 14.5).
In 2016-17, Gordon Hayward recorded career highs in usage rate (using 27.6 percent of the Jazz's possessions while he was on the floor), effective field goal percentage (53.6 percent) and true shooting percentage (59.5 percent).
Al Horford shot 43 percent from 3-point range last season, up from 36 percent in 2016-17. That was the second biggest jump in 3-point percentage among 100 players who attempted at least 200 threes each season.
Kyrie Irving registered career-high marks in both usage rate (using 31 percent of the Celtics' possessions while he was on the floor) and true shooting percentage (61.0 percent) last season.
Irving had an effective field goal percentage of 61.3 percent as a pick-and-roll ball-handler, according to Synergy tracking. That was the second best mark (behind that of Stephen Curry) among 104 players with at least 100 pick-and-roll-ball-handler field goal attempts. His effective field goal percentage of 55.5 percent on pull-up jumpers also ranked second behind Curry (minimum 150 attempts).
Irving had an effective field goal percentage of 66.2 percent after the All-Star break, up from 55.8 percent before the break. That was the biggest jump among 203 players with at least 250 field goal attempts before the break and 100 after it, and it came with a big jump in the percentage of his shots that were 3-pointers (36 percent before the break, 50 percent after it).
Marcus Morris was the only player to shoot less than 50 percent at least 50 restricted-area attempts in the playoffs.
Semi Ojeleye had a usage rate of just 9.1 percent, lowest among players who averaged at least 15 minutes in 40 games or more.
Terry Rozier shot 32 percent on drives, the worst mark among 154 players who attempted at least 100 shots on drives.
In the playoffs, Rozier shot 45 percent (31-for-69) on catch-and-shoot 3-pointers and just 22 percent (16-for-72) on pull-up 3-pointers.
Only 4.9 percent of Marcus Smart's points (27/550) were fast break points. That was the lowest rate among guards who scored at least 500 total points last season.
In the playoffs, Smart had an effective field goal percentage of 38.8 percent, the second worst mark among 92 players with at least 50 postseason field goal attempts.
Jayson Tatum shot 30-for-51 (59 percent) on clutch shots, the best mark among players who attempted at least 50.
Tatum shot 54 percent on corner 3-pointers, the best mark among players who attempted at least 50.
Tatum scored 351 points in the playoffs, one shy of Kareem Abdul-Jabbar's rookie record of 352, set (in only 10 games) in 1970 (when he was Lew Alcindor). Tatum's 683 postseason minutes also rank second all-time among rookies (behind Jack Sikma - 701 in 1978).

This is amazing when you remember how many players Danny has shuttled through here over those five years, how bad we were for the first two of them and how new Brad was.


bob


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