Arseneault played for his father — as a point guard at Grinnell, he averaged more assists than any player in Division III history — before joining him on the bench as an assistant coach. Then, one day in 2014, the Sacramento Kings called: They were interested in hiring David Arseneault Jr. to coach the Reno Bighorns, their affiliate in the N.B.A. Development League. Not only that, the Kings wanted him to conduct one of the bolder experiments in D-League history by installing the Grinnell offense.

“They gave me a lot of flexibility,” he said.

Arseneault spent two seasons with the Bighorns. In his second season, he coached them to a 33-17 record and a Pacific Division title. But when his contract was not renewed — the Kings had a new front office — Arseneault returned to Grinnell, where he took over for his father. Last season, the Pioneers finished with a 13-11 record while averaging 111 points a game.

“We’re still tweaking our offense,” he said. “It’s a process.”

In recent weeks, Arseneault has been studying how N.B.A. playoff teams create space with pick and rolls — an aspect of his own system that he wants to improve. On Monday night, he was also interested to see how the Warriors and the Rockets handled defensive switches in those situations.

“It’s so hard not to switch in the N.B.A. these days,” Arseneault said, “because teams will just hunt for those matchups.”

In the game’s early moments, Clint Capela, the Rockets’ young center, found himself defending Curry on the perimeter after a switch. Arseneault figured the Warriors would try to exploit that sort of matchup, even though analytics have shown that Capela is one of the league’s more effective big men when it comes to defending smaller players.

Curry attempted to use his quickness to drive past Capela, and he appeared to have a half-step on him as he rose for a layup. But Capela recovered to swat the shot away. Arseneault, who coached against Capela in the Development League, was impressed.