Birth Year Wine Case Allocation

If you were buying a birth year case of wine for someone, e.g., child, niece, nephew, etc., which you planned to drink with that person at special occasions as the person grew up (graduations, wedding, etc.), how would you allocate the twelve bottle selection? Would you buy a case of a single wine like a classed growth Bordeaux to watch the vintage evolve over time, or would you mix it up with wines and styles from around the world? I'd be curious to know what wines people would choose in an ideal birth year gift case and why. Not necessarily producers, but styles and regions. Thanks in advance!