Markus Oliphant (23), shown during a game against Old Mill last February, has overcome personal tragedy to help lead the Wildcats into Tuesday’s Maryland 4A East semifinals. (Jonathan Newton/WASHINGTON POST)

Markus and Anthony Oliphant used to play basketball together every day. Some days, the brothers would just hang out and shoot casual baskets. Sometimes they would play one-on-one — sibling rivals incessantly trying to one up each other.

But in pickup games, the brothers stuck together. United, they felt unstoppable.

Oct. 23, 2012 was one of those days. Markus, a senior guard at Arundel, and Anthony found themselves in a game of four-on-four, on the same team as always. For the first time in his career, Markus was a starter this season for the Wildcats, and his basketball tutor was his older brother.

“We ran up the court, we won like eight in a row,” Markus said. “We didn’t get off the court.”

That was the last time the brothers would play together. The next day, Anthony Oliphant Sr. found his son dead from an enlarged heart. Anthony Jr. was sitting in his white Dodge Charger with his shoes off, Anthony Sr. said, “like he was listening to music and had just dozed off and didn’t wake up.”

Markus (left) and Anthony Oliphant Jr. were brothers and teammates. (Courtesy of the Oliphant family)

Anthony Sr. tapped on the car’s window, then shattered it, and checked his son for a pulse. When he didn’t find one, he called his wife, then 911. Markus was in the car with his mother when she got the news. It hit her hard enough that she couldn’t finish the drive home, so Markus took the wheel the rest of the way.

“I didn’t believe it at first. I didn’t believe it was real until like, weeks after to where it really sunk in,” Markus said. “Still today sometimes I think he’s still alive, but I know he’s not. It’s that emptiness that you get.”

Amidst his grief, Markus has blossomed on the court this winter, and the Wildcats are rolling as a result. Arundel hosts third-seeded Meade in Tuesday’s Maryland 4A East region semifinals.

The 6-foot-3 guard is the team’s third leading scorer this season, averaging 11.9 points per game on a team so balanced that its top four scorers all average within five points of one another.

Much of Markus’s increased effectiveness for the Wildcats this season has come from his improved shooting, a skill he says he picked up from his brother. As a senior in high school, Anthony Jr. hit 63 three-pointers for Hoke County High School, a conference record that still stands today. Markus estimates 80 percent of his jump-shooting ability is the result of hours spent in the gym with his brother.

Markus’s versatile game allowed him to switch positions earlier this season, from power forward to guard. He brings energy as a rebounder and his long, lean frame has allowed him to defend larger opponents nearly every night. The 2012-2013 season has been the best of Markus’ basketball career — and nobody would have enjoyed it more than Anthony Jr.

“My brother was my number one fan, always. Every game, summer league games, AAU, no matter what it was, he was always courtside, rooting me on,” Markus said. “He was always into the game, and he got our other fans into the game. He just brought that energy to every single home game, every away game, anything.”

Anthony Jr. was hard to miss. He insisted on sitting courtside, near center court where his cheers and jeers would have maximum effect. The day after he died, Markus’s teammates talked about how Anthony Jr. was always the loudest voice, letting them know what they were doing right and what they were doing wrong.

“He was always in the front row, always cheering us on, coaching from the side. I know he was always hard on me, hard on everyone, but that was his way of making us better,” Arundel senior guard Austin Carroll said. “He always was saying something for us. We felt like he had our backs all the time.”

Anthony Jr.’s funeral was held in Georgia six days after he died, but Markus’s grieving process lasted another two or three months. It took Markus a month before he was able to go back to the gym. The first time back, Markus went to the gym with three friends. The second time, he went alone and couldn’t bring himself to pick up a ball. He lifted weights instead.

Markus’s first game without his brother on the sideline, a Dec. 5 win over River Hill, was even tougher.

“The first game, after the game, I just started crying,” Markus said. “In the car, I just started crying because he wasn’t there. It was a lot of empty everything going on. I actually felt sick after the game.”

Markus still thinks about his brother every day, usually when he prays at night or as he’s falling asleep. But as the pain has subsided, the happy memories have surfaced. He almost never thinks about his brother during games, but once in a while during warm-ups, he can almost see his brother out of the corner of his eye, back in his old courtside seat.

“When I’m doing things, I envision him being there,” Markus said. “Definitely at every basketball game, I just envision him being there.”