- Created runner_advancement.py with complete groundball advancement system
- Implemented GroundballResultType IntEnum with 13 rulebook-aligned results
- Built RunnerAdvancement class with chart lookup logic (Infield Back/In)
- Implemented all 13 result handlers (gb_result_1 through gb_result_13)
- Added DECIDE mechanic support for interactive runner advancement decisions
- Implemented double play probability calculation with positioning modifiers
- Created 30 comprehensive unit tests covering all scenarios (100% passing)
Key Features:
- Supports Infield Back and Infield In defensive positioning
- Handles Corners In hybrid positioning (applies In rules to corner fielders)
- Conditional results based on hit location (middle IF, right side, corners)
- Force play detection and advancement logic
- Double play mechanics with probability-based success (45% base rate)
- Result types match official rulebook exactly (1-13)
Architecture:
- IntEnum for result types (type-safe, self-documenting)
- Comprehensive hit location tracking (1B, 2B, SS, 3B, P, C, LF, CF, RF)
- Dataclasses for movements (RunnerMovement, AdvancementResult)
- Probability modifiers: Infield In (-15%), hit location (±10%)
Testing:
- 30 unit tests covering chart lookup, all result types, and edge cases
- Double play probability validation
- All on-base codes (0-7) tested
- All groundball types (A, B, C) verified
Status: Week 7 Tasks 4 & 5 complete (~87% of Week 7 finished)
Next: Task 6 (PlayResolver Integration)
Related: #task4 #task5 #runner-advancement #double-play #week7
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