Then upon what do you base your disbelief?
Incomplete =/= useless. However, if you don't feel this evidence is useful, what are you putting stock in?
Not sure that I've noticed any previous One Brow illustrations of this particularly statistical non-trend, but I found it interesting and a bit surprising. I would have also thought the Jazz under Sloan to have been a sub-par team when related to 3-point stats. But all hope is not lost.
While interesting, I found the stat to be a bit shallow. Percentage only tells part of the story. Volume is another question. During that 11-year span, the Jazz averaged a rank of 7th in the league in Opponent 3PA/FGA (at around 23% of opponents' field goals being 3-point attempts - league average was 20.5%. - San Antonio consistently ranked low with a ridiculous 16% average). With the Jazz being quite average in terms of Opponent 3P%, the fact that they allow more threes as a percentage of overall shots than the average team lends some credence, in my opinion, to the theory that the Jazz are sub-par at defending the three. In reality, this translates to about one more opponent 3-point shot attempted than the league average per game. Have fans really been shaking their heads over that one extra shot for the last 20 years, or are we just a bunch of hypersensitive ninnies? I'm going with "b".
What really caught my eye looking at those statistics, however, was the low opponent FGA when compared to the rest of the league, coupled with an extremely average opponent PPG. The correlating statistic: Utah is the king of Opponent FTA. What does this tell me? I don't know. Other than that the Jazz hack you to bits when you drive to the hoop, probably because all 5 defenders are there waiting for you.
Next Study of Grand Importance: How have the Jazz fared compared to the rest of the league in opponents' free throw percentage (at a quick glance, the statistical variation there appears to be just as pronounced as it is in three point percentage). I've noticed a dramatic decrease in Jazz players clapping their hands and/or raising them into the air while opponents are shooting free throws. A concerning pattern, indeed.