Dwight, Dirk and D-Wade have become fallen stars in #NBArank

Father Time is undefeated, to borrow one of Charles Barkley's favorite lines -- one he has been using in discussions about Dirk Nowitzki for at least five years now.

It's an easy explanation for why Nowitzki, 39, barely made ESPN's #NBARank top 100 and his two-time NBA Finals foe Dwyane Wade, 35, didn't make the cut.The drop of 31-year-old Dwight Howard is a bit premature to attribute to Father Time's merciless powers, but he joins Nowitzki and Wade as former superstars who slid from the #NBArank top five in 2011 to the 40s last year, before flirting with the triple digits after the voting from our esteemed panel was tallied this summer.

With several assists from ESPN Stats & Information's Jose De Leon, here's a look at the declines of these three future Hall of Famers, of which only one -- Nowitzki at No. 97 -- managed to crack the current list of the NBA's top-100 talents.

Howard: Hero for hire

The center who fancied himself as Superman has become a journeyman, joining his fifth team in seven years when his hometown Atlanta Hawks unceremoniously dumped him in a trade to the Charlotte Hornets one disappointing season into a three-year, $70 million deal.

Howard's divorces from the Orlando Magic, Los Angeles Lakers and Houston Rockets weren't pleasant, but this marked the first time that a team simply had no interest in keeping the five-team first-team All-NBA selection. Atlanta's shift into full-fledged rebuilding mode under new management might have influenced the decision, but the simple fact is that Howard didn't make the Hawks better during his one season with the Hawks.

Atlanta was outscored by 2.0 points per 100 possessions when Howard played last season; the Hawks were plus-0.7 points per 100 possessions with him off the floor. As much as it bothered Howard, coach Mike Budenholzer had good reason to bench him during fourth quarters in the playoffs.

Howard remains a dominant rebounder, ranking fourth in the NBA in rebounding percentage last season, grabbing 23.5 percent of the available boards when he was on the floor. However, with his explosiveness diminished significantly by injuries, the three-time Defensive Player of the Year is no longer an impact player on that end of the floor. He averaged a career-low 1.2 blocks per game last season, a figure he at least doubled in four previous seasons. There was no difference in the Hawks' defensive rating with Howard on or off the floor.

Howard has become a hindrance to his team on offense, in part due to his reluctance to run the pick-and-roll, a source of friction in his dysfunctional, passive-aggressive relationship with Rockets superstar James Harden. Howard prefers to be utilized as an old-school, post-up player, a dinosaur in the modern NBA, even though he isn't effective in that role. According to NBA.com tracking, Howard averaged the most post touches in the league last season (8.0 per game) but ranked in the 37th percentile in post scoring efficiency (0.84 points per possession).

Howard's scoring averages the last two seasons (13.7 in Houston, 13.5 in Atlanta) have been his lowest since he was a teenage rookie and so have his usage rates (18.4, 19.2).

Howard has attempted to modernize his game this summer, working on his 3-point shot. It's a curious plan for a player who is a career 8.9 percent 3-point shooter (5-for-56), sixth worst in NBA history (minimum 50 attempts).

And while Howard doesn't turn 32 years old until December, he has already played more NBA regular-season games (954) and minutes (33,291) than Wade despite entering the league a year later.

A better reason for hope that Howard can reverse his recent trend of decline: his reunion with Hornets head coach Steve Clifford, a trusted assistant coach and confidante during the best years of the big man's career.

"I know what he has to do to play well," Clifford said after the trade to acquire Howard. "He understands that I know him. I know his game. Being around him in different settings I have a feel for what he likes to do ... There is no reason he can't get back to playing at a really high level."

Wade: Searching for new home?

Wade can certainly relate to Howard when it comes to awkward homecomings. Wade threw a wrench in the Chicago Bulls' rebuilding plans when he exercised his player option for this season and was totally transparent about money being his motivation: "24 million reasons," he told TNT's David Aldridge, well aware that he wouldn't have commanded that kind of a salary on the open market this summer.

So Wade and the Bulls are engaged in a staring contest, a buyout ultimately in the best interest of both parties, neither of which is willing to make it a financially painful transaction at this point. If and when Wade and the Bulls agree on a buyout, a question will be answered: How much can he still help a contender?

Wade didn't help the Bulls much during a .500 campaign last season. They had a plus-2.1 net rating (points per 100 possessions) when he was off the floor and minus-2.4 when he played, the worst swing among Chicago starters.

Wade's scoring average (18.3 points per game) was certainly respectable, but it was his lowest since his rookie year, which was the last time he wasn't an All-Star before last season. He had career lows in field goal percentage (43.4) and assists (3.8 per game) as his minutes declined for the fourth consecutive season.

Nowitzki: Down but not out

Precious few players in NBA history have been as productive as Nowitzki was last season at 38 or older. Only Kareem Abdul-Jabbar, Michael Jordan, Karl Malone and Reggie Miller have averaged more points per game at that age than Nowitzki put up last season, his 19th in a Mavericks uniform.

That's a positive way to spin a season in which Nowitzki, whose sweet shooting as a 7-footer revolutionized the NBA, had his worst numbers (14.2 points per game, 43.7 field goal percentage) since he was a rookie, and the Mavs finished with a losing record for the first time since 1999-2000.

Nowitzki, the sixth member of the 30,000-point club, remains an elite catch-and-shoot threat. Only Golden State's Klay Thompson averaged more points on catch-and-shoot opportunities last season than Nowitzki (8.0 per game). Nowitzki's shooting percentage on such plays (44.5) tied for sixth in the league among players with at least five attempts per game.

The Mavs continue to be a much more efficient offensive team with Nowitzki on the floor, due in large part to the respect defenses must pay him and the space that creates. Dallas averaged 3.7 more points per 100 possessions with Nowitzki on the floor than when he sat once the calendar flipped to 2017 last season, which coincided with the big German fully recovering from the sore Achilles tendon that sidelined him for most of the season's first two months.

But Nowitzki, who self-deprecatingly refers to himself as a mummy due to his stiffness and lack of mobility, increasingly has to be hidden on defense and is no longer capable of creating on the isolation plays on which he was virtually unstoppable throughout his extended prime. (Harrison Barnes has inherited that section of the Mavs' playbook.)

"Now, I'm still trying to compete," Nowitzki told ESPN last season. "I enjoy doing it. Obviously, it's not as easy as back in the day. All the extra work you have to put in to stay ready. Now dealing with injuries that I really never had, it takes the fun away a little bit, but hopefully I can [stay healthy] and have fun."