Where is the pressure?
Pressure = Leverage (how much the next ball can swing win probability) × Difficulty (behind par on wickets and asking rate) × Stage. Compare three win-probability models and both innings.
▦Heatmap · overs × wickets down
Pressure rises sharply when wickets fall in the first overs of a chase (3 down in overs 1–4: 64%) and when 6–8 wickets are down late (7 down in overs 17–20: 80%), but not when a side is 0 down late. That is the Leverage × Difficulty logic working.
◧Powerplay / middle / death · 3 models
Logistic Regression floods the chase powerplay with "pressure" and ignores first-innings middle overs, so XGBoost, which learns over × wicket × runs interactions, defines the main index.
✓Does pressure really make batting harder?
The Pressure Index also tracks genuinely close matches: 1.43 in finishes decided by ≤10 runs or ≤3 wickets vs 0.90 in one-sided games.
