Only 1% of defensive three-second violations have been called correctly in the final two minutes of close games since the start of the 2015-16 NBA season, Owen Phillips writes for The F5 newsletter.
Using publicly available data from the league's last-two-minute reports, Phillips found that just two defensive three-second violations - in which a defender spends more than three continuous seconds in the paint without actively guarding an opponent - have been correctly assessed compared to 194 incorrect non-calls since 2015.
That 1% correct-call rate pales in comparison to those of more common infractions, such as personal fouls (87.8%), shooting fouls (75.6%), and even traveling (23.5%).
Phillips also noted that whistles for defensive three-second violations peak far earlier in games than whistles for several other foul calls, with a significant drop-off in the second half and fourth quarter.
The expansion of modern NBA offenses toward the perimeter is one potential explanation Phillips offered for why referees have seemingly paid less attention to impropriety in the paint.