Mark that appears four times in this puzzle (hint: the baseball player who's the answer to this puzzle uses one, too)

Question:

Length:

Similar Crossword Questions:

Today, to CaesarÂ—and a hint to the hidden word appearing in this puzzle 15 times (including the one in this answer)
Drink cooler ... or a hint to six squares in this puzzle's answer
Number of times the letter 'U' appears in each of this puzzle's eight longest answers
Sidelined by injury, in baseball lingo, and a hint to how this puzzle's theme puns are formed
Puzzle theme which appears nine more times in the grid
Minimum number of times each letter of the alphabet appears in this puzzle's solution
Achieves a rare baseball feat, delineated by part of each long puzzle answer
Baseball ... with a hint to this puzzle's theme
Letter that appears at least once in every single answer in this puzzle
Bridge player's need, and hint to this puzzle's theme
___ accent, mark used symmetrically six times in this puzzle's solution
Third base, in baseball lingo ... or a hint for answering eight other clues in this puzzle
Start of a brainteaser whose answer appears in order, from top to bottom, in this puzzle's circled squares
Lois Lane player of early TV, whose first name is a hint to this puzzle's theme
It appears several times in this puzzle, so fill'er up!
Pro baseball level ... or a hint to 12 answers in this puzzle
Temporarily not playing, in baseball lingo (and a hint to this puzzle's theme)
Number of times this puzzle's theme word appears diagonally in the grid (to complete the puzzle, shade those words plus the Down answers that begin where they meet)
Platform ... or something that appears four times in this puzzle?
"I'm freezing!" and a hint to this puzzle's theme
Environmental slogan, or a hint to this puzzle's theme answers
What every other letter of every answer in this puzzle is
What each theme answer in this puzzle does
What each of the 10 abbreviations in this puzzle's answer stands for
Word that can precede each set of circled letters, forming a literal hint for entering certain answers in this puzzle