This example shows a family tree of football players, rendered as an animated SVG diagram with circular nodes connected by grey paths. It uses d3.stratify to convert flat parent-child data pairs into a hierarchy, then d3.tree to compute the layout. Circle nodes are colored by generation depth via a switch statement, and transitions animate both path connections and node radii over short durations. Text labels identify each player, while the tree expands from a single root node downward.