Pretty soon he started hitting a few, and on Friday night he was a career-best 6 of 6 from behind the arc.
Parsons scored 21 points and the Rockets picked up their fourth straight win, rolling to an easy 114-95 victory over the Brooklyn Nets.
"I started the season shooting really poorly," Parsons said. "It's all about staying confident and sticking with it and just continuing to put in the work in the gym. I've worked too hard for it not to start paying off."
The Rockets led by 26 points at halftime and Brooklyn coach Jason Kidd benched all his starters except Brook Lopez for the entire second half.
"We had to go with the guys who were going to play hard," Kidd said. "Those were the guys, and I played them the whole second half."
Houston made a season-high 19 3-pointers, led by the perfect night by Parsons, who scored all his points in the first three quarters.
"If you get ball movement that we want and body movement that we want, we should be able to get open 3s," coach Kevin McHale said. "We are one of the teams that looks for it and shoots a lot of them."
James Harden scored nine points with seven assists for the Rockets in his return after missing three games with a sore left foot. He played almost 26 minutes.
Lopez was also back after sitting out the last six games with a sprained left ankle. He started in place of Kevin Garnett and scored 16 points in about 21 minutes.
"The last three teams have great 3-point shooting teams and we gave them easy looks from that distance," Lopez said, adding that he felt great after the game.
Kidd said he thinks his starters weren't playing hard because they were fatigued before this trip after playing in Toronto on Tuesday before a home game against the Lakers on Wednesday.
"That's a problem," he said. "We have to address that ... we've got to figure out what the problem is with our starting group."
Brooklyn shot just 33 percent overall in the first half and only 10 percent from 3-point range. Brooklyn's backups didn't fare any better. Houston used an 8-2 run in the third quarter to make its lead 80-48. Parsons had a 3-pointer during the run and Terrence Jones also scored three points.
The Rockets led by 16 with about five minutes left in the second quarter before using a 16-6 spurt to push the lead to 66-40 at halftime. The Nets missed seven shots, had two turnovers and allowed the Rockets to have easy look after easy look as they built the lead.
The Rockets led 33-17 at the end of the first quarter.
Houston scored the game's first six points and was up by four before using a 13-0 run to extend the lead to 25-8 with about three minutes left in the first quarter.
Howard missed a hook shot at the end of that run before Casspi grabbed the rebound and tossed a no-look, backward pass to Garcia. His 3-point attempt bounced off the rim but Howard was there to tip it in.
Harden showed that he was feeling good early when he juked Joe Johnson off the dribble at the top of the key, drawing an `ooh' from the crowd, and dashed into the lane for a wide-open layup. He missed it, but Howard was there to grab the rebound and finish with a dunk.
Kidd said he was just "trying to win" when he intentionally spilled a drink on the court, a stunt that cost him $50,000. "It's about trying to win and those guys in that locker room, and I tried to put those guys in a position to get a basket, a good look and we did," he said. ... Houston's Jeremy Lin will miss at least two weeks with a sprained right knee he sustained in Wednesday night's game. Coach Kevin McHale said before the game that they'll know more about his status in about 10 days or so. ... Former Rockets star Mario Elie watched the game from a courtside seat. ... Brooklyn's Mirza Teletovic had a career-high 13 rebounds.