Free throws over expected vs free throw rate

How is free throws over expected different from free throw rate?

Free throw rate counts trips to the line per shot. Free throws over expected asks whether a player draws more than his situations usually produce, which separates a player who seeks contact from one who simply shoots a lot of layups.

Free throw rate (FTr)

Free-throw attempts per field-goal attempt.

FTr = FTA / FGA

Side by side

Free throws over expected vs free throw rate: what each measures
YesNo
Adjusts for shot contextYesNo
BaselineThat season's own league rateNone
Rewards a rim-heavy dietOnly above what the rim usually drawsYes, fully
UnitAttempts per 100 possessions vs expectationRatio

Which should you use?

Free throw rate is the simpler description. Free throws over expected is the one that isolates the part not explained by where a player shoots.

What neither measures

Neither distinguishes contact-seeking skill from the officiating a player happens to receive.

Definitions: Free throws drawn over expected per 100.

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