The Celtics’ Rajon Rondo has been impressive in the playoffs, averaging 13.5 points and 8.5 assists per game.

The Providence Journal / Kris Craig

WALTHAM, Mass. — When the first round of the Eastern Conference playoffs started, the one position that Atlanta believed it had an advantage over the Celtics was at point guard.

After all, Atlanta starting point guard Mike Bibby entered the series with 51 games of playoff experience and Boston second-year guard Rajon Rondo had none.

Bibby entered the series averaging 17.9 points, 5.6 assists, and 3.6 rebounds per playoff game.

Rondo, who would still be in college if he stayed all four years at the University of Kentucky, spent his rookie NBA season on one of the worst Celtics teams in franchise history. He averaged 6.4 points, 3.8 assists and 3.7 rebounds per game last season.

But Rondo has outplayed Bibby in every aspect of the game so far in this series.

“He’s playing terrific,” Boston coach Doc Rivers said.

Rondo is averaging 13.5 points, 8.5 assists, 6 rebounds and only 0.5 turnovers per outing in the series. He is also knocking down an impressive 60 percent of his shots (12-for-20) from the field. Bibby is averaging just 8.5 points, 3 rebounds, and 1 assists per game, and 1.5 turnovers per outing in the series.

Rondo has held Bibby to a lowly 23.5 shooting percentage from the field (4-for-17).

“My goal going into this series was to try to keep track of my man and keep him in check,” Rondo said.

So far so good.

“I just try to pick him up full court, bother him a little bit, and transition defense, that’s where he’s been real aggressive and KG [Kevin Garnett] and Perk [Kendrick Perkins] have been helping me get back,” Rondo said.

Bibby said that Rondo is having a good series because Atlanta is focusing on trying to stop Boston All-Stars Paul Pierce, Ray Allen and Garnett, and not Rondo.

“He’s playing good,” Bibby said of Rondo. “The main thing we are trying to do is see what he can do out there. They have the big three out there, and the main focus is them three. He is stepping his game up and hitting his shots, and we are going to let him shoot it.”

Ask Rondo’s teammates and coaches and they will tell you that Rondo’s game has vastly improved over last season and he is quickly becoming one of the better two-way guards in the Eastern Conference. “I just want to stay consistent and play my role and do my job,” Rondo said. “If I have to score and knock down some open shots then that’s what I’ll try to do. Hopefully, I just rise to the occasion.”

Rondo is the pace-setter for the Celtics and Rivers said Rondo’s decision-making has been superb so far in this series.

“He’s come a long way,” Rivers said.

Rivers said that much of Rondo’s success is because he is a video fanatic. He watches up to two hours of game tapes a day.

“Rondo and Kevin [Garnett] would be the top two, but Rondo, by far, is the film-watcher on the team,” Rivers said. “I was really impressed with him at the first practice going into the playoffs. We would introduce a [Hawks] play and before we’d put a name to it, Rondo was calling ‘three-up, four-down.’ You don’t see that very often.”

Rondo said that he watches himself on tape to see if he could have made better decisions, and to learn the opposition’s defensive tendencies.

Rondo has been studying game tapes since his high school days in Louisville, Ky.

It has certainly been a factor in how well he has played in this series. Even if Bibby won’t give Rondo the credit he deserves, it has been Rondo who has been the better player between the two.

The Celtics fans said it loud and clear Wednesday night when they chanted, “Rondo’s better,” over and over again in the fourth quarter. next game

at Atlanta

Tomorrow

8 p.m.

roblee@projo.com