Gar-Field junior guard Zach Fong’s decline coincided with that of his grandfather, Richie Cumming. Upset after observing his maternal grandpa’s deteriorating physical condition a few weeks ago, Fong fell into a shooting slump, his mind burdened by the realization that the fun-loving family patriarch he once thought would live forever had perhaps entered his final days.

So last weekend before No. 14 Gar-Field hosted Osbourn in the Virginia AAA Northwest Region championship, Fong reported to the gym early to try to rediscover his shooting touch and take his mind off news he had gotten that afternoon about his grandfather having another rough day.

Fong met at least one of his objectives. He nailed a long jumper a minute or two into the game and tacked on seven more three-pointers in scoring a career-high 31 points in a 76-64 win that gave the Indians their first region title since 2003.

Fong will try to continue his hot streak in the state quarterfinals at 6:30 p.m. Saturday at Robinson against Eastern Region runner-up Kecoughtan. Prior to erupting in the region final, Fong had totaled only 42 points in his previous six games.

“Before the [Osbourn] game,” Fong said, “I prayed and told myself this game is going to be for my Grandpa. Every step I take on this court is for my Grandpa tonight. The fact that we won and I had a really good game, it really meant a lot to me.”

“He’s had such a hard time for the last two or three weeks and then all of a sudden, as soon as he hit [the first one], it was like, okay, here we go,” said Patti Fong, Zach’s mother, who does not expect her father to make it home from a rehabilitation center in Alexandria. “You can tell by Zach’s attitude. He gets this grin on his face.”

There certainly have been a lot of smiles shared with his grandfather through the years. Cumming, 79, suffering from diabetes and cancer, used to babysit Fong, taught him poems and tricks — including one that makes it look as if you’re sliding your finger off and on — and took him to University of Maryland basketball games during the Steve Blake-Juan Dixon era.

Along with other relatives, the two spent a lot of time at a home on the Chesapeake Bay that has been in the family for generations, visits filled with crabs, kayaks, corn on the cob, gin rummy and board games. Fong took note of his grandfather’s zest for life and has heeded his if-you-start-something-finish-it advice.

“We’ve been really close from the day I was born,” Fong said. “[His physical state] definitely affects me every single day. I always go to bed thinking about him, wake up thinking about him. He’s always on my mind.”

Gar-Field Coach Andy Gray made Cumming a DVD of the region final so he could watch Fong’s breakthrough game. The eight three-pointers were a large chunk of Fong’s 66 this season. He is shooting 39 percent from three-point range and is averaging 11.8 points.

Fong attended O’Connell his freshman year, sometimes commuting with fellow Prince William County resident and future North Carolina point guard Kendall Marshall, a senior at the time. Fong trains with Kendall’s father, Dennis, and the younger Marshall keeps up with him from Chapel Hill.

“Heard my lil bro Zach got off from Gar-Field yesterday. told y’all he was nice,” Kendall Marshall tweeted on Sunday.

Cumming attended a Gar-Field game late in the season, before he began chemotherapy for a cancer in his neck. The treatments were aborted after they so ravaged his body that he had to be hospitalized.

After that game, Fong said hello to his grandfather on the way into the locker room, but Cumming had been wheeled away by the time he came back out. Fong could tell that his grandpa was pleased to have seen him play at least one last time.

“He didn’t say much but, ‘Good game,’” Fong said. “But that was good enough for me.”