April 17th is a great day in Pittsburgh Pirates and baseball history.

But which of his 18 MLB seasons were best? How do we decide that? Most home runs, hits or runs? Best batting average? No -- we're past that these days.

Using the advanced metric that is FanGraphs' Wins Above Replacement (WAR), we are able to see which five stand out most among the rest. How? This single number summarizes a player's total contributions to their team and is an estimate of how many wins they add to his team over the course of a season.

Through this very lens of today's sabermetrics, let's take a look back at a historically great player so we can more vividly see how impressive Roberto Clemente's best seasons are.