Stats review: Pick-and-roll defense

Two of the top three teams in Group B of the 7DAYS EuroCup Regular Season faced off in Round 8, with Gran Canaria scoring a hard-fought home victory over Buducnost VOLI Podgorica. While the win itself was important, the way Gran Canaria won may have been even more significant.

Gran Canaria entered the game having allowed 1.10 points per possession created out of pick-and-rolls – the worst mark in the EuroCup at that time by a significant margin. Last week, however, the Gran Canaria defenders put together its best effort of the season by far, holding Buducnost to just 28 points over 36 possessions derived from ball screens. While they had some issues with fouls on those possessions, they did an excellent job extending their hedges and rotating to shooters without giving up easy opportunities around the rim.

Gran Canaria is an interesting case study in the complex relationship EuroCup teams have with the pick-and-roll at the moment. It is the unmistakable cornerstone of many set offenses, serving as the origin of 43% of half-court possessions. However, its value has dipped this season. For the first time in recent history, the average half-court possession has been more valuable than one generated out of the pick-and-roll with, although both are hovering right around 0.93 points per possession.

That makes Gran Canaria's difficulty in getting stops puzzling and outright confounding when considering the graph above, which looks at which teams have done the best job limiting high-quality pick-and-roll outcomes measured in points per-shot. As the graph suggests, Gran Canaria has not only done a good job limiting high-value attempts, but has forced turnovers at a strong rate as well. Their defensive Synergy Shot Quality – the expected value of the attempts they allow as determined by a data-driven model – has actually been slightly better than average against pick-and-rolls this season.

That all begs the question: how does a team whose process is sound find themselves on the wrong end of the leaderboards? While many of Gran Canaria's issues comes on the ball, some of it can be traced to the little things like untimely fouls, slightly late rotations, and a lack of length in spots. However, even if there's a variety of factors at play, it is also apparent that luck has not been kind to Jaka Lakovic's team this season. That readily apparent in the 49% that opposing pick-and-roll ball handlers have shot from beyond the arc against Gran Canaria – an outlier so far beyond league averages that a regression to the mean is basically a formality at this point.

In stark contrast, the four best pick-and-roll defenses this season in terms of points per possession are also in the top six in the graph above. Most teams tend to reap the benefits of what they sow defending the pick-and-roll. Paris Basketball falls in that group to an extent as perhaps this season's second most interesting case, as its shot defense has been sublime. Paris thrives in rotating and protecting the rim and therefore gives up a remarkably low volume of quality attempts while forcing a ton of low-percentage long two-point jumpers. Despite that, Paris rank just fourth in overall pick-and-roll defensive efficiency because its low volume of turnovers forced on opponents leaves it susceptible to teams whose shot-making supersedes the significant impact of Paris's shot defense.

With individual EuroCup teams allowing a broad range of points per possession created out of pick-and-rolls so far – from a low of 0.77 points to a high of 1.05 – plus coaches making constant adjustments to their nuanced schemes and some teams simply getting unlucky, the defensive landscape in the league is fairly blurry at the moment.

If things remain as unpredictable as they are right now with these types of inequities and wild swings, it could make this year's single-elimination playoffs even more exciting and chaotic than last year's.