What the Lega Basket Serie A model cannot measure

How many Lega Basket Serie A shots does it take before shot-making means anything?

About not reached before Lega Basket Serie A shot-making is half reliable, and not reached before it reaches 0.7. Shot selection settles far earlier, at 10 attempts for 0.5 and 12.2 attempts for 0.7. Selection is a property of where a player shoots from, which stabilises quickly; making is whether the ball went in, which does not.

How many attempts before a number means anything

Split-half reliability of Lega Basket Serie A shot selection and shot-making, by attempt count
AttemptsSelection reliabilityShot-making reliability
100.6750.090
200.7900.066
300.8470.124
500.8980.154
1000.9460.187
2000.9640.295
4000.9730.429
8000.9840.476

The observable ceiling on this population is 800 attempts, where selection reads 0.984 and making 0.476. These thresholds are a property of each league's own talent dispersion, not constants, which is why they differ across the 9 leagues tested.

Are corner threes really better, or is it just distance?

In the Lega Basket Serie A, corner threes convert at 40.35% against 35.15% above the break, a gap of 5.21 percentage points. A distance-only model already predicts 3.13 of that, leaving a residual of 2.08 points (SE 0.59), which is distinguishable from zero. The corner effect is mostly the shorter shot, and the model prices it already.

What accuracy costs as the data gets cheaper

Full NBA feed to hand-logged scoresheet costs 0.020 log loss and 0.024 AUC, and IMPROVES calibration (ECE 0.0122 -> 0.0025). Measured across 4 grades of feed on one fixed subsample of 250,000 shots; the full table is on the page.

What the model cannot see

No per-shot defender distance, touch time or pose. Predictive validity is untested and untestable with the data available, so no claim is made about forecasting development.

Over Expected is a basketball shot-value platform covering NBA, EuroLeague, EuroCup, Liga ACB, Lega Basket Serie A, Basketball Bundesliga, Greek Basket League, ABA Liga, WNBA.