While the NBA and fans bid a fond farewell to 13-year veteran center Jason Collins, there is another reason beyond his courageous coming out that he’ll be remembered – he’s also considered a pioneer in the NBA’s advanced stats movement.

There’s no question that Collins’ coming out will go down in history – he became one of the important “firsts” in the history of the LGBT sports diversity movement – the first openly gay active player in one of the U.S.’s big four professional sports leagues.

However, there is another reason for Collins to be remembered in sports history. In 2005, according to Neil Paine, senior sportswriter for FiveThirtyEight, Collins “headlined a group of unsung players whose value was only beginning to emerge via a new metric known as adjusted plus/minus (APM).” This new metric “attempted to determine how much effect an individual had on his team’s per possession scoring margin. And Collins, whose meager per-game averages would normally render him invisible to statistical analysts, had a far greater one than his conventional stats would suggest.”

In his article Paine included the following more detailed account of Collins’ worth on the hard wood. “According to [APM expert Dan] Rosenbaum’s calculations, Collins is not a stiff at all but one of the NBA’s premier defensive centers: the fourth-most effective in the league over the last three seasons,” SI’s Chris Ballard wrote before the 2005-06 NBA season. “Over the last three seasons the Nets have been remarkably more effective at the defensive end with Collins in the lineup; they foul less, allow fewer free throws, rebound better and allow fewer points. ‘He’s very consistent and consistently very good,’ says Rosenbaum, ‘meaning he’s either the luckiest center alive and teams just fall apart when he’s on the court, or he’s doing something.’”

So looking at Collins’ career stats, an average of 3.6 points and 3.7 rebounds per game and a lifetime player efficiency rating (PER) of 7.0, Paine says it’s an “astonishing accomplishment.” He continues to say that if “every player’s RAPM (minimum 10,000 minutes played) against that which we would expect solely from his PER, a useful per-minute proxy for the conventional statistical perception of a player, Collins comes out as the NBA’s most underrated player of the past decade and a half.”