Stats say Dikembe Mutombo belongs in Hall of Fame

Dikembe Mutombo will be inducted into the Basketball Hall of Fame on Friday. During his career, Mutombo was not universally regarded as a Hall of Famer. But the stats speak strongly in his favor -- particularly the advanced stat known as adjusted plus-minus.

Mt. Mutombo and the finger wag

The name Mutombo is synonymous with defense and blocked shots. Famous for his finger wag after yet another rejection at the rim, "Mt. Mutombo" was generally seen as perhaps the best defender of his generation.

In his long NBA career, spanning from 1991 to 2009, Mutombo won four defensive player of the year awards, made six All-Defensive teams, led the league twice in defensive rebounds (finishing 11th all-time) and recorded more blocked shots than any player in history other than Hakeem Olajuwon. (Of note, blocks weren't an official stat until the 1973-74 season, shortchanging many greats, including Kareem Abdul-Jabbar).

Clearly, the box score numbers and the award voters in his day pegged him as an all-time great defender.

Did his teams win enough?

Critics can cite Mutombo's lack of team success to knock his Hall of Fame case: In his 17 years in the NBA he made the NBA Finals just once as a starter, with the Philadelphia 76ers, in Allen Iverson's MVP season. The Sixers lost to the Los Angeles Lakers in five games. In his other Finals appearance -- also a losing effort, with the New Jersey Nets -- he played less than 12 minutes per game.

On the whole, in his 18 seasons, Mutombo's teams saw only limited success. In most seasons they did not make the playoffs (five times) or lost in the first round (seven times). In four other seasons, his team lost in the second round , including his final season, when Mutombo was a bit player at age 42.

Probably Mutombo's most memorable playoff series came in 1994 when his eighth-seeded Denver Nuggets upset the top-seeded Seattle SuperSonics, a team that won 63 games, featuring Gary Payton and Shawn Kemp. Mutombo, almost 28 years old though in just his third season, blocked 31 shots to set the record in a five-game series (which he still holds), visibly frustrating Kemp on several occasions. It was the first No. 8 vs. No. 1 upset in NBA history.

Was it Deke or his teammates?

During his first 10 seasons, with Denver and Atlanta, Mutombo was selected for the All-Star Game seven times but played with only two All-Stars: Steve Smith and Christian Laettner each made the All-Star team once when Mutombo was a Hawk. Near the end of his 10th season, at age 35, Mutombo joined perennial All-Star Allen Iverson in Philadelphia and then made one more All-Star Game the following season.

Therefore, rather than dwell on his postseason shortfalls, we might just as easily focus on Mutombo's ability to carry mediocre teammates. For most of his career, Mutombo, like Kevin Garnett in Minnesota, was the best player on his team, and he rarely got to pair his talents with those of other stars.

Adjusted Plus-Minus: the more complete picture

The box score numbers and individual honors suggest that Mutombo was a defensive force worthy of the Hall of Fame, but were those numbers hollow? Was Mutombo racking up meaningless stats on so-so teams? Or were his accomplishments meaningful in terms of making his team better?

Fortunately we can estimate player impact without relying on box score numbers. Adjusted plus-minus estimates a player's impact on his team's performance -- on wins and losses. (Adjusted plus-minus is also the basis for Real Plus-Minus, which employs both play-by-play and box score data.)

For this analysis we have two data sets: One of them covers the middle section of Mutombo's career, the four seasons from 1996-97 to 1999-2000. The second covers the latter section of his career, the nine seasons from 2000-01 to 2008-09.

Using data from, adjusted plus-minus tells us that Mutombo ranked first in defensive impact among all players from 1996 to 2000, rating almost a full two points per 100 possessions better on defense than the next-best player. Overall, Mutombo ranked fourth in impact (including the offensive end), behind only Michael Jordan, Shaquille O'Neal and Kevin Garnett.

Analysis of the latter data set, from 2000 to the end of Mutombo's career, tells a similar story.

When we adjust for age (which puts all the players on more equal footing, since Mutombo was 34 at the start of this phase of his career), Mutombo was a slight negative on offense but was so dominant on defense that he was still one of the best players in the NBA. His age-adjusted defensive impact was second only to Garnett's in that era (among 1,467 players), putting Mutombo ahead of defensive stars Alonzo Mourning, Ben Wallace and Dwight Howard.

Mutombo and Mourning

Another way to look at whether a player belongs in the Hall of Fame is to compare him to a similar player who has been inducted.

Not only were Mutombo and Mourning teammates at Georgetown University and NBA contemporaries, but they also had fairly similar career accomplishments -- though arguably they fell a little short of the standard set by another Georgetown center of the same era, Patrick Ewing.

Zo won two defensive player of the year awards and made seven All-Star teams, putting him slightly behind Mutombo in both categories. Mourning was more of a scorer, although at the price of committing more turnovers and recording fewer offensive rebounds. Mourning also won a championship ring (albeit as a backup to O'Neal in Miami) and an Olympic gold medal.

Mutombo, on the other hand, racked up more rebounds on each end and blocked shots for his career (Mourning holds a slight advantage in blocks per game). And Mutombo's defensive dominance, as measured by adjusted plus-minus, more than makes up for any gap in their respective offensive abilities.

Mourning was inducted into the Hall of Fame in 2014. There's no doubt Dikembo Mutombo deserves to follow him to Springfield this year.