Earning your “stripes” in today’s NBA – Numerical Nuance after 50 games

Before the advent of the three-point field goal, playing “winning” basketball was a rather simple proposition – a team needed to convert more of its scoring opportunities than the other guys, and then make sure they didn’t squander that advantage with shoddy free-throw shooting.

But nowadays – with the impact of that added “stripe” to the court – a team may well out-convert the opposition yet wind up losing on the scoreboard.

Take Boston’s Nov. 1 TD Garden Party with the Milwaukee Bucks as an example. On the strength of a 30 – 13 edge in free-throw attempts, the visitors were successful on 53 of their 100 possessions while the C’s registered but 47 conversions. But Milwaukee misfired on eight foul shots while connecting on nine three-pointers – thus earning one “stripe.” The Stevens Gang, on the other hand, missed only two FT’s while draining 24 (out of a whopping 55 attempts) treys – good for 22 “stripes” and a four-point Celtic victory.

Of course, that knife cuts both ways – as evidenced by a bad Boston loss at Orlando on Jan. 12. The Celts out-converted the Magic by four but were out-striped by 10 in a 105 – 103 defeat. (This loss was most infuriating, as the C’s were +12 in points-following-turnovers, +4 in Follow-Up points and +4 in FTA’s.)

Despite a handful of such disappointing setbacks, the Celtics reached Game 50 of their schedule last night against Brooklyn on a pace to win 51 games or so – likely good enough for a Top-Three seed in the Eastern Conference playoff bracket.

Controlling the “Flow”

Coach Stevens’s crew has registered more conversions than their opponents 30 times so far in 2018-19. Five times have they recorded an advantage of 10 or more, and on six other occasions have they held an edge of at least five conversions – all 11 games resulted in a victory.

When converting between one and four more opportunities than their opponents, the Celtics have been victorious in 15 of 19 games.

Overall, Boston is 26 – 4 when controlling the game’s Flow.

When out-converted, our boys stand just 3 – 15; the C’s won both games when conversions were even.

The Added-value of “Striping”

Despite an appearance and manner right out of the 1950’s, Boston bench leader Brad Stevens is as sabermetrically savvy as any coach around and clearly embraces the modern-day “3>2” hoops philosophy.

“Striping” – successful three-balls “minus” missed free throws – is my “simple-metric” way of tracking the impact of distance shooting in a league where better than a third of all FGA’s come from behind the arc.

Brad’s boys have held an edge in this little computation in 35 games so far – and have won 27 of them. Their most improbable loss from this perspective came on Nov. 3 in Indiana … the Celts were +11 in stripes, but the Pacers six-conversion advantage forged a one-point win.

On the season, Boston is 0 – 9 when the opposition out-stripes them by at least four.

Through the season’s first 12 weeks (40 Celtic games), the C’s were earning 9.42 stripes per game (No. 1 in the league) to their opponents’ 4.70 (No. 8) – their +4.72 per-game differential ranks No. 2 to Houston’s +5.60. (Worthy of note is Houston’s usage rate/3PAr of .504 compared to Boston’s .401.)

The half-season’s Top-Five in Striping Differential were rounded out by Golden State (+2.86), Toronto (+2.10) and Brooklyn (+2.00).

Analysis Paralysis

While the raw numbers needed to compute “Striping” are easily obtainable, the computation of possessions and conversions is the result complicated formulas – and are thus merely estimates as opposed to an actual tally. In the matter of conversions, for example, there’s no way of knowing how many converted possessions are represented by, say, 17 FTA’s – other than by scanning the play-by-play, which gets tedious (trust me!!).

Thus, I try to use the available data to “compute” Empty Possession. For instance, take a team’s missed FGA’s, subtract its offensive rebounds, then add its Turnovers … compute the same data for the team’s opponents. Finally, divide by the number of games to get per-game totals – which can then be ranked.

By that Math – and again through 12 weeks – Boston records 2.30 fewer Empty Possessions per game than does its opponents. That placed them No. 6 in the NBA.

The Top 5? Milwaukee (-4.28), Indiana (-3.20), Oklahoma City (-2.95), San Antonio (-2.48) and Toronto (-2.42).

The March to Banner 18

Despite Gordon Hayward’s continuing struggles to discover that elusive “zone” of unconsciousness when he isn’t micro-managing every “landing” …

Despite Jayson Tatum’s occasional entrapment in the dreaded “Sophomore Slump” …

Notwithstanding the coaching staff’s precautions with Al Horford’s aging legs and Kyrie Irving’s tendency to sprains and strains …

During the Second Quarter of 2018-19 (Weeks 7 – 12, Nov. 28 – Jan. 9), the Boston Celtics ranked in the Top Ten both offensively and defensively in each of the following categories:

Points per Game (No. 1; No. 4)
Field Goal Percentage (No. 3; No.5)
3FG Percentage (No. 4; No.5)
Turnover Percentage (No. 6; No. 6)
“Flow” (No. 6; No.9)
“Striping” (No. 1; No. 8)

Maybe the most mind-boggling component to this six-week stretch when the Celtics went 14 – 5 is that their opponents attempted 5.95 more free throws per game – second-worst differential in the league.

Abacus Revelation for the Road

By the numbers, the C’s most glaring area of concern is the matter of Follow-Up Points.

While the Offensive Rebounding Totals themselves (through 14 weeks/48 games, this time) don’t appear alarming – including “significant” Team Rebounds, opponents hold a 525 – 502 advantage – the other guys have produced 614 “F-U” points to Boston’s 502. That’s an edge of more than two points per game.