1) Berra caught his perfecto 2) Captain in a jack london book 3) Danish chess master 4) Danish surname 5) Don of 1956 World Series fame 6) Don who spun perfect WS game 7) Jack London captain 8) Jack London character 9) Jack London protagonist 10) Patronymic surname 11) Perfect game pitcher Don 12) Perfect-game pitcher Found on https://www.crosswordclues.com/clue/larsen