In the 1985 version of his annual Baseball Abstract, sabermetrics pioneer Bill James introduced the "Keltner List" as a method of assessing whether players belong in the Hall of Fame. The Keltner List, a series of questions summarizing a player's career, has been adopted by basketball.
Neil Paine of FiveThirtyEight even used it in a series for ESPN Insider a couple of years ago.
Today, though, I want to focus on a specific question posed by the Keltner List:
"Is [this player] the very best player in [NBA] history who is not in the Hall of Fame?"
Since Artis Gilmore earned his long-overdue spot in the Naismith Memorial Basketball Hall of Fame in 2011, there hasn't been a clear answer to the question. Excluding players new to the ballot, I think there is one player who now stands above his peers as the best overlooked by the Hall of Fame: Former Seattle SuperSonics and Milwaukee Bucks center Jack Sikma.
The Case for Sikma
Note: In full disclosure, I am a little biased here. Sikma helped lead my favorite team, the Sonics, to their only championship in 1979. Having settled in the Seattle area, he later worked for the team as an assistant coach at the same time I did while covering the Sonics for their website. So as much as possible, I'm going to rely on numbers to make the case for me. Though Sikma isn't necessarily tops in every important category, he ranks among the leading non-Hall of Famers in several of them.
Let's start with Win Shares, the James-inspired measure of player value that Basketball-Reference.com has tracked through 1977-78 and estimated before that, making it the most complete list. Among eligible Hall of Famers who have not been selected, Sikma ranks third (and 51st overall):
Because of the way it credits 3-point attempts for their spacing effect, my wins above replacement player (WARP) stat is not quite as favorable to Sikma. He ranks a bit lower despite the fact that I've only calculated WARP back through 1977-78, the first season player turnovers were tracked (and, coincidentally, Sikma's rookie season):
For a last measure of player value, we can look at Basketball-Reference.com's value over replacement player (VORP) stat, calculated from their box plus-minus statistic.
Here, Sikma ranks 44th in NBA history, though there are a few more eligible players not in the Hall of Fame ahead of him:
Each all-in-one stat comes up with a slightly different list. But nobody's ahead of Sikma on all three of them. The strongest argument for Sikma is probably looking at All-Star appearances. As we lament each February, the All-Star process doesn't always pick the best 24 players in the league.
Still, it's a good way to capture how players were viewed in their time. Sikma was chosen for every All-Star Game from 1978-79, his second season, through 1984-85.
And while that total of seven might not sound remarkable, only one eligible player not in the Hall of Fame has more All-Star selections: 1950s center Larry Foust, who made eight appearances in an era where there were typically more than twice as many spots on the All-Star roster (20) as teams (eight).
In fact, as Justin Kubatko noted in looking at Sikma's Hall of Fame candidacy earlier this year, Jo Jo White's selection means every eligible Hall of Fame candidate with precisely seven All-Star appearances save Sikma has been chosen. Even if we expand the criteria in either direction to look at players with between six and eight All-Star selections, 33 out of 38 eligible players have made the Hall of Fame.
As a result, Basketball-Reference.com's Hall of Fame probability suggests an 87 percent chance of Sikma being chosen based on his statistics and honors. The aforementioned Foust is the only eligible player with a higher Hall of Fame probability who has not been chosen.
Sikma not in consideration?
Given all that, it's strange that Sikma has never even been chosen a finalist by the Hall of Fame's selection committee. Perhaps his career doesn't resonate with voters. While Sikma won a championship and went to a pair of Finals with the Sonics, they came during one of the league's most forgettable eras. He played NAIA college basketball at tiny Illinois Wesleyan University and spent his entire NBA career in the outposts of Seattle and Milwaukee. To the extent Sikma is part of the basketball zeitgeist at this point, it's mostly because of his famous blonde perm from the 1980s.
In part, that's probably explained by the fact that Sikma was very good for a long period of time rather than great. He never made an All-NBA team, since the two center spots were locked up by Kareem Abdul-Jabbar and Moses Malone during his prime. (Hall of Famer Robert Parish, in 1981-82, was the only center to displace them between 1978-79 and 1985-86.) Sikma did finish in the top 10 in MVP voting twice, peaking at seventh in 1978-79.
Some of this, too, can surely be explained by the Hall of Fame's opaque voting process and nebulous standards. When compared to players elected over the past five years, Sikma's core résumé compares favorably. (See chart at bottom)
That might not necessarily make Sikma the very best eligible player who's not in the Hall of Fame, but it certainly makes him a deserving candidate for enshrinement in Springfield, Massachusetts.