The baseball infield is called a 'diamond,' yet the shape formed by the bases is a square. Why is a square called a diamond? The answer involves a simple but profound shift in perspective.
Watch a baseball game from above and you'll notice players spend a disproportionate amount of time facing left. Right-handed batters face left, runners circle counterclockwise, and fielders orient leftward tracking batted balls. Baseball is structurally a leftward-facing sport.
The distance between bases is 90 feet (27.43 meters), unchanged since the 1840s. One meter longer and infield hits would vanish. One meter shorter and ground-ball outs would nearly disappear. Ninety feet is the miraculous equilibrium where human running speed and throwing speed are perfectly balanced.