NBA Three-Ball: Usage vs. accuracy, a riddling equation


I’ve got a question for you – sort of a riddle. Here’s the situation.

Team A, playing at home, is successful on 51 percent of its two-point shots, compared to 45 percent for Team B. Team A also makes four more free throws, while Team B connects on two more three point shots and grabs four more offensive rebounds. The teams commit an equal number of turnovers.

How does the visiting Team B win this game by eight points?

Think it over for a minute – there’s a very logical answer.

The explanation that straightens out the apparent incongruity of such an outcome is revealed twice in the box score of this NBA game of recent vintage.

Despite the significant gap in those shooting percentages, Team B actually converted three more “deuces” than did Team A by virtue of 14 more 2FG attempts.

The consequence of such a wide discrepancy in this category – particularly when, as in this case, the TO, FT and OR columns are relatively even – is a somewhat equal but opposite reaction with the three-point shooting. And since many box scores don’t offer data on 2FG’s, this little “indicator” is easier to spot.

Here’s what Team B did that night – they were able to make more three-point shots than the other guys while attempting fewer, in this case two more “makes” on eight fewer “tries.”

Overall, the “B” Team converted five more FG’s and out-shot Team A 46 percent to 43 percent. Here are the gory details of that disappointing Celtic defeat at the hands of their “Best of Enemies” nearly 18 months ago.


Now, I can already hear all you Centennial-Millenials mumbling out there, “There goes that old fart again, finding a new way to say, ‘Get offa my lawn, and take your damn three-point gimmick with you.’”

But just bear with me for a second – things are not always what they seem.

What cannot be denied is that usage of the three is not just rising, but soaring … even Memphis mentor “Data” Dave had his traditionally snail-paced, post-centric dinosaurs knocking down 40 percent of their long balls in four separate playoff match-ups with a Spurs’ squad who’d ranked No. 5 in defending the stripe.

In the “riddling” game, the winners got the best of all outcomes for the “Three Game” – better “return” (points) from less “investment” (attempts). Naturally, there are three other possible outcomes: fewer points from fewer attempts, fewer points from more attempts, more points from more attempts.

[NOTE: For several reasons, 3FG% and Usage Rate (i.e. 3PAr) seem more “reliable” rather than the actual number of makes and attempts, and therefore were utilized in the following analysis.]

In the early years of the three-ball, almost all deemed the tactic speculative and unnecessarily risky, a reckless temptation designed for undisciplined free spirits like World B Free.

But from Year 1 (1979-80) there was also on display an intelligent approach to the use of this new weapon, demonstrated best by Celtic teammates Chris Ford and Larry Bird.

[OOPS – the ’79 Bird/Ford story is the third section of the linked posting that was once a slide show, entitled “The Deceptive Volley.” Bleacher Report always seems to have a new surprise for me when I try to access my older work. Sheesh!!]

And ever since, the basketball world has been “In Search of …” the optimal balance of Usage and Accuracy. Amongst the more accomplished of the current Searchers is our own Brad Stevens.

Let’s see if we can figure out which style of the “Three Game” has worked best over the past two seasons for his champions-in-embryo.

In the Dec. 30, 2015 home loss to the Lakers – where we started all this – the C’s higher usage rate and lower rate of accuracy than LA’s resulted in a loss. Boston’s offense replicated that pattern in 21 other games that season. The Stevens Crew was 9-13 in those contests … not too shabby, really.

But this year’s Atlantic Division champions didn’t fare so well under those apparently unfavorable conditions, dropping 18 of the 24 games in which they took more but made fewer. Likewise, the Celtics have won only one in seven such playoff performances over the last two years.

In all, nearly half (31) of Boston’s 63 regular-season losses have come in games where their 3Par is higher than their opponents’, but their 3FG% is lower.

As they say, it’s a Make-or-Miss league … so what happens when it’s the other guys chunkin’ up all those loooong bricks?

IT4, Horford and the boys managed to attempt “less” but convert “more” just 11 times in the regular season, unsurprisingly winning 10 of these games. Their predecessors had posted a not-quite-as-lofty 14-3 slate whilst performing under these favorable conditions. And this evolution of Celtic Pride stands 3-1 in playoff competition under these circumstances.

This “Don’t shoot a whole bunch but make ‘em when ya do” approach makes me think of a Popovich team playing at its best.


In its last 164 regular-season games, the Stevens C’s have both taken and made treys at a higher rate than the opposition 61 times and have won 48 of those games … a slightly more modest seven out of 11 in the playoffs. Boston was 29-6 (7-3, post) this season when launching their threes so freely and confidently.

The Celtics ended up on the flip-side of these trey-rates only 29 times, going 6-11 in 2015-16, then 8-4. The group has yet to win a playoff game when “minus” in both usage and accuracy.


Recent Boston Three-Ball

plus-Usage / plus-Accuracy: 2015-16, 19–7 -- 2016-17, 29–6
plus-Usage / minus-Accuracy: 2015-16, 9–13 -- 2016-17, 6–18
minus-Usage / plus-Accuracy: 2015-16, 14–3 -- 2016-17, 10–1
minus-Usage / minus-Accuracy: 2015-16, 6 – 11 -- 2016-17, 8-4


Over the past two post-seasons, the team that shot the three-ball more accurately won four out of every five games (124 out of 165). Hell, simply taking more treys resulted in victory in well over half the games (90 out of 165). Here’s the full break-down:

plus-Usage / plus-Accuracy: 2015-16, 38 winners -- 2016-17, 32 winners
plus-Usage / minus-Accuracy: 2015-16, 6 winners -- 2016-17, 12 winners
minus-Usage / plus-Accuracy: 2015-16, 29 winners -- 2016-17, 25 winners
minus-Usage / minus-Accuracy: 2015-16, 11 winners -- 2016-17, 8 winners

[NOTE: Over the past two post-seasons’ 165 games, there were three times when both teams’ 3FG% was equivalent, and one occasion when their 3PAr was the same.]


From the looks of all this “digital” evidence, the three-point shot has taken up permanent residence on basketball’s Lawn.

Maybe I should have called this “NBA Three-Ball: Usage + accuracy, a riddling equation?" (After all, “vs.” ain’t no mathematical operation – and you call yourself an abacus. Harumph!!)


Abacus Revelation for the Road

Not infrequently in the course of seeking “visual adornment” for my postings, something that “makes me go ‘Hmmm’” is attributed to celticslife.com – Jo Jo White playing for the Warriors; some weird-angle shot where it looks like Cowens is jumping into the balcony; unusual, generally dated kind of stuff like that.

Invariably, the image comes from one of TB’s world-famous WTHHT pieces. What’s up with that? 


Images: (Stevens) boston.com, (Free) nba.com, (nerd) clipartall.com, (Pop) thesource.com