Just because the NFL now allows teams to challenge pass interference calls and non-calls does not mean it is going to make it easy for coaches to win them.

Oakland Raiders head coach Jon Gruden has found that out the hard way thus far in 2019, as he made his fourth pass interference challenge of the season on Sunday during his team's win over the Detroit Lions and lost for the fourth straight time.

However, Gruden's lack of success in pass interference challenges is not going to stop him from throwing the flag in the future.

“We’re challenging things that we think are plays that are going to be overturned and we’re going to trust the process,” Gruden said, according to Adam Hill of The Las Vegas Review-Journal. “So far, I’ve been given the Heisman. I’ve been stiff-armed. I’m 0-for-27, I think. But when I listen to people tell me they’re going to overturn a call because it’s the wrong call, I believe in the process. And I still believe in it.”

Gruden is now 0-for-6 on challenges overall this year and has never been a big proponent of instant replay to begin with, but as long as it's available to him, he will try to use it to his advantage.

As for the Raiders?

Oakland improved to 4-4 with its victory over the Lions and is very much alive in the AFC playoff picture, something that hardly anyone expected when the Raiders lost Antonio Brown before the season.

Gruden's club doesn't have much time to celebrate its most recent win, as it will take on the Los Angeles Chargers in a pivotal AFC West clash on Thursday night.