It all happened so fast Sam Hornish Jr. didn't really get a chance to realize exactly what was going on.

Chasing down Marco Andretti during the final yards of the 2006 Indy 500, Hornish swept past the son of racing royalty to win by about a car length, the distinct rumble of the yard of bricks under his wheels at the finish line telling Hornish he'd finally captured the most-coveted title in open-wheel racing.

"I couldn't have scripted it any better," Hornish said.

The fairy-tale finish hasn't necessarily led to happily ever after for the three-time Indy Racing League champion during his rookie season in NASCAR's Sprint Cup.

The winningest driver in IRL history returns to familiar territory for Sunday's Allstate 400 At The Brickyard in an unfamiliar position: struggling to find the magic that seemed to flow so easily during Hornish's dominant open-wheel career for team owner Roger Penske.

"We've been on a roller coaster, been on a lot of lows and we're waiting for it to come back up," said Hornish, who is 33rd in the Sprint Cup standings. "When we started out the season, we thought if we could be in the top 25 in points, win rookie of the year (it) would make it feel like a wonderful season."

Hornish still has a realistic shot at catching Regan Smith for rookie of the year honors. Finding a way to sneak into the top 25 could be more difficult. Hornish hasn't finished higher than 13th in any of his 19 starts this season thanks to a mixture of the circuit's steep learning curve and a little bad luck.

"We really should be in the top 25 in points," Hornish said. "I've made mistakes and we've made mistakes as a team."

Even on days when the car appears to be right, strange things seem to happen. Hornish was running second in the LifeLock 400 in Michigan last month when a hot dog wrapper got stuck on his car's grill causing the engine to overheat. He ended up 22nd.

"I live for days like Michigan, where I feel like I could have won," he said. "It's not every day you feel like that."

Those days have been rare this year for a driver who won 19 IRL races before jumping to the Sprint Cup following the 2007 season. While Hornish didn't expect a seamless transition, he also didn't expect to spend so much time at the back of the field. His average finish over his last four races is 34th.

"You always feel like you should be able to head in the right direction," he said. "We've had some things that have been pretty tough, days when no matter what we did we couldn't make the car any better."

Though his patience has been tested, Hornish doesn't regret making the move to NASCAR even after the IRL and ChampCar merged this winter, unifying American open-wheel racing for the first time in over a decade.

"In the IRL you felt like you could win every day, (but) I felt like I wasn't getting the challenge that I needed," he said. "It was time for something different."

Hornish hasn't ruled out a return to the IRL, though it would likely be an occasional cameo on Memorial Day weekend, much like Tony Stewart has done in the past. The thought of riding the Indy 500 during the day then hopping a plane and running the Coca-Cola 600 later that night is intriguing.