Below you can find the Modern baseballs have a core made of cork; back in the day the core was this material Jeopardy Words Answer. The answer to Modern baseballs have a core made of cork; back in the day the core was this material has 6 letters. This clue belongs to the Back in the day category and is part of Jeopardy Word Level 2514. If you scroll near the bottom you will find other clues and answers part of level 2514