While the Pro Football Hall of Fame's 2020 induction class is full of deserving inductees, there were a few notable senior candidates who were not part of this year's class. 

At the top of that list is former Raiders receiver Cliff Branch, a three-time Super Bowl champion who earned four Pro Bowl selections and three consecutive All-Pro selections during his 14-year career. Branch, whose blazing speed helped modernize the passing game, led the NFL in receiving yards and touchdown receptions in 1974, his third NFL season. Two years later, he paced the NFL in touchdown receptions while helping Oakland capture its first Super Bowl win. In the early '80s, Branch's continued excellence helped the Raiders win two more Super Bowls, as Branch became one of the most prolific postseason receivers in NFL history.

Despite his accomplishments, Branch, who died in 2019 at age 71, never received the call to Canton. His family, however, continues to have faith that Branch's career will one day be immortalized in the Hall of Fame.

"It would mean the world to us," said Elaine Anderson, Cliff's sister. "It would mean everything to us, because we know that he's deserving. His records speak for itself. It would mean everything to us."

Anderson, who attended each of Branch's Super Bowl wins with her siblings and parents, said that her brother always believed that he would one day earn induction into the Hall of Fame.

"He dreamed of it. He actually thought that he was going in one day," she said. "He talked about it. And it was like so positive: 'When I go into the Hall of Fame.' He just felt, 'Hey, I've earned it, I'm worthy, and it's going to happen.' My sadness is that he's gone now, and I still believe he's going. It's not that I don't think he's going, I'm just sad because he's not here to witness it. And I think, when you work that hard, you ought to be the one to witness your accolades, your awards."

A three-time All-Pro and three-time Super Bowl champion, Cliff Branch is also fourth all-time in career postseason receiving yards. Getty Images

Branch would not be the first Raider to be posthumously inducted into the Hall of Fame. In 2016, a year after he died, Ken Stabler -- Branch's quarterback -- was inducted. Like Stabler's supporters prior to his induction, Branch's supporters are trying to figure out what's taking so long.

"I don't know what it is," Anderson said. "I'm searching my heart. I'm reading about players who are in, versus him not being in. I don't know what it is, but I'm not giving up hope."

While he played in an era where the passing game was still an offense's secondary mode of transportation, Branch's numbers rival any other receiver from that era. He has more career receiving yards than Lynn Swann, whose career is enshrined in Canton. He has more career touchdown receptions than Swann's teammate, John Stallworth, who is also in the Hall of Fame. Branch has more catches, receiving yards, touchdowns and Pro Bowl selections than Drew Pearson, who was also bypassed for induction into the Hall of Fame this past year. Branch has three more All-Pro selections than Harold Carmichael, who is part of this year's induction class. 

As good as Branch's regular season stats are, his postseason numbers are truly what sets him apart from his peers. Branch is currently fourth all-time with 1,289 career receiving yards, trailing only Jerry Rice, Julian Edelman and Michael Irvin. Branch, who averaged 17.7 yards per reception during the postseason, has as many Super Bowl rings as Rice, Edelman and Irvin. His three Super Bowl touchdown receptions are tied with Swann, Stallworth and Rob Gronkowski for second all-time, behind Rice.

Branch's longevity also helped set him apart. At an age where most receivers hang up their cleats, Branch was still playing big in big games. In Super Bowl XV, a 32-year-old Branch caught two touchdown passes in Oakland's 27-10 win over Carmichael's Eagles. Three years later, in Super Bowl XVIII, a 35-year-old Branch set the tone for the game with a 50-yard catch that set up his 12-yard reception, the first offensive score of the game. The Raiders never lost momentum, drubbing the defending champion Redskins, 38-9.

Unlike many players of his era, Branch trained year-round, a regiment that allowed him to play at a high level into his late 30s.

"He always trained," Anderson said. "He trained in season and out of season. He ate the right kind of food. He'd get up early in the morning and work out and run and just whatever he needed to do to stay in shape."

Branch excelled catching passes from both Stabler and Jim Plunkett, who saw a career rebirth shortly after joining the Raiders. Both passers benefited by having Branch, whose speed could break open a game while keeping opposing defenses on their toes.

"Every game that we went to, we saw signs that said: No. 21: Speed Kills," Anderson said. "They didn't have to put his name on it because we knew what they were talking about. We knew. That was just amazing."

Anderson said that Branch first started dreaming of playing pro football when he was playing with the family's electric football set as a child. She also recalled witnessing Branch's speed, and his competitive drive, at their father's Fourth of July company picnic when they were in sixth grade. During the picnic, there was a race, where the winner would receive Chinese Checkers, a prize Branch was determined to win.

"Clifford ran so hard and so fast, he won the race," Anderson recalled, "and he got that game of Chinese Checkers. So on the way home, we had to hear that on the way home: 'I won! I won!' 

"So it was really at that point when we knew that he could run. We didn't know that before then. So when he got to junior high school the coaches found out that he could run. And they started working with him and training him. But when he got to high school, he was on fire, and I think that's when they taught him how to run."

From there, Branch played college football at Colorado, where he averaged 25.4 yards per catch during his last season with the Buffaloes. A year later, he was drafted in the fourth round by the Raiders, where he would help the Silver and Black become one of pro football's all-time great teams.

"They were bad boys," Anderson said with a laugh. "They were all special in their own way. I think what they focused on was the team effort. This is about our team, and they always considered themselves a family. They were all good. At whatever position they played, they were excellent. But it took the whole team to win the game. One person couldn't win the game by himself."

While his family continues to take pride in the three Super Bowl wins, Anderson said that Branch's connection to his fans may have been his favorite part of playing pro football.

"He totally understood that they loved him," she said. "And I'm telling you, there wasn't a game where you didn't see 'No. 21: Speed Kills.' Somebody had to put it up, and he loved that. And he always took time for his fans. He loved his fans. I think his fans helped him become great."

Branch also surely would have enjoyed seeing his career immortalized in Canton, something Anderson and the rest of Branch's family hopes comes to fruition sooner rather than later.

"I'm now saying, how about 2021 for No. 21," Anderson said. "It's going to happen. And I'm still holding on to 2021."