The Week 1 NFL preseason slate ends with a showdown between the Los Angeles Chargers and Arizona Cardinals on Saturday. Kickoff is at 10 p.m. from University of Phoenix Stadium. Cardinals fans are eager to get their first peek at UCLA quarterback Josh Rosen, who was drafted in the first round, and their team enters as 2.5-point home favorites. Before you lock in your Chargers vs. Cardinals picks, you have to see what SportsLine stat geek R.J. White has to say.

White knows what it takes to win on football's biggest stage. He finished in the top 1 percent of the Las Vegas SuperContest last season after also cashing huge in 2015. That's right -- he has crushed the world's most prestigious handicapping tournament twice in the past three years.

If you had placed $100 on each of White's NFL point-spread picks last season, you would have won nearly $2,000. Smart bettors tail him.

Now, with the NFL regular season fast approaching, White has locked in his point-spread pick for Chargers vs. Cardinals on Saturday. He's only sharing it over at SportsLine.

We can tell you White is leaning Under 36 points, but his much stronger play is on the spread, which is available at SportsLine. And you need to see what it is -- White is on an amazing 11-3 run in spread picks for or against Arizona.

White knows the Steve Wilks era begins in Arizona, taking the reins after the retirement of Bruce Arians. While Wilks has been coy as to how much action Rosen is expected to get Saturday, expect to see him on the field most of the night. First-stringer Sam Bradford, making his Arizona debut, isn't expected to get many snaps.

Limited action is also likely for Cards running back David Johnson, who missed 15 games last year due to a dislocated wrist. With star safety Tyrann Mathieu signing with the Texans, backup safeties Tre Boston and Antoine Bethea should get plenty of action in the secondary.

Back at the helm in his second year is Chargers coach Anthony Lynn, looking to build off a 9-3 finish to the 2017 season.

With quarterback Philip Rivers beginning his 15th NFL season, he is not expected to play more than one series. Cardale Jones, Nic Shimonek and Geno Smith are all vying to be his backup. With Melvin Gordon expected to play sparingly and rookie Justin Jackson nursing a hamstring injury, expect to see second-string running back Austin Ekeler in the backfield often.

White has evaluated each roster from top to bottom and has unearthed a critical stat that determines which side you should be all over.

So which side of the spread should you back for Los Angeles vs. Arizona and which critical stat determines the outcome? Visit SportsLine here to see which side you need to be all over, from the expert who keeps crushing the Las Vegas SuperContest, and find out.