Tempo Quantification (Actual vs. Expected Speed)

Defining tempo as the average difference between actual ball speed and expected ball speed across a set of passes: tempo = mean(actual_speed - expected_speed). A player or team that consistently passes faster than expected given the spatial context plays at a "high tempo." This separates meaningful tempo (quick combinations through tight spaces) from meaningless speed (long clearances that happen to be fast). The chess analogy: tempo is gained when you accomplish an objective with fewer moves (or faster passes) than expected; lost when you take extra time. Accumulating these deltas reveals which players, teams, and pass types consistently play faster or slower than context predicts.

(1) Compute expected ball speed for every pass using the expected-ball-speed-model. (2) For each pass, compute delta = actual_speed - expected_speed. (3) Aggregate by player, team, match, phase of play, pass type, or any other dimension of interest. (4) Positive mean delta = high tempo (passing faster than context demands). Negative = low tempo (passing slower than context allows). (5) Analyze which situations produce the highest tempo — are there specific pass types, pitch zones, or game states where a team plays significantly faster than expected?

Key insight: this is NOT possessions per game (basketball tempo). Stoke City under Pulis topped raw ball speed rankings but wouldn't score as "high tempo" because their fast passes were long clearances into contested space — expected ball speed for those situations is already high. Barcelona's short combinations in tight spaces are "high tempo" because expected speed there is low but they execute quickly.

1. Using raw ball speed as tempo: Long clearances are fast. They're not tempo. Always adjust for context.
2. Confusing tempo with possession: Barcelona has high tempo AND high possession. They're correlated but not the same — a team can have low possession but play at high tempo in transition.
3. Not accounting for game state: Trailing teams often increase tempo (desperation passing). Leading teams may decrease tempo (game management). Tempo changes within a match are as informative as the aggregate.