| Name | Lines of code | Maintainability | Test coverage |
| src/Board.php | 408 | B 4 hrs | A 100% |
| src/FEN.php | 629 | F 3 days | A 100% |
| src/Move.php | 147 | A 0 mins | A 100% |
| src/NotImplementedException.php | 6 | A 0 mins | F 0% |
| src/PGN.php | 209 | A 1 hr | A 100% |
| src/ParseException.php | 6 | A 0 mins | F 0% |
| src/RulesException.php | 6 | A 0 mins | F 0% |
| src/Square.php | 130 | A 0 mins | A 100% |