I submit that on Wikipedia, you can get from the page of any mathematician to Leibniz’ page in 6 clicks or less (even without clicking through the “Mathematician” or “Mathematics” links that show up in like the first sentence of every mathematician’s Wiki page).

Fun Examples for Fun

Starting mathematician: George Polya
Click 1: Probability Theory
Click 2: Probability
Click 3: Christiaan Huygens
Click 4: Gottfried Leibniz

Starting mathematician: George Boole
Click 1: Differential Equation
Click 2: Derivative
Click 3: Gottfried Leibniz

Starting mathematician: John Venn
Click 1: Set Theory
Click 2: Principia Mathematica
Click 3: Philosophiæ Naturalis Principia Mathematica
Click 4: Gottfried Leibniz

Starting mathematician: Sewall Wright
Click 1: Philosophy
Click 2: Gottfried Leibniz

Starting mathematician: Henri Poincaré
Click 1: Bernhard Riemann
Click 2: Riemann Integral
Click 3: Integral
Click 4: Gottfried Leibniz