Who is Philip Rivers?

Well, that depends on which of his 7,637 career passes you’re watching.

Sometimes, he’s “elitely accurate,” as his new boss, Colts coach Frank Reich, called him Wednesday, four days before the Vikings visit Indianapolis.

Over a 17-year career, 16 of them with the Chargers, Rivers ranks ninth in completion percentage at .647.

Other times, Rivers looks like a rookie in need of a good benching.

In Sunday’s 27-20 upset loss to Jacksonville, Rivers handed the Jaguars 10 points by throwing the 199th and 200th interceptions of his career. Another one was negated by penalty.

His first interception was a high-risk gamble typical of Rivers. Throwing off his back foot as he was being hit, Rivers trusted the receiver to come down with a ball thrown to the sideline.

“That first one was on me,” Reich said. “I made a wrong call and put him in a bad position and that resulted in an interception. Although there were two interceptions last week, I would only put one on [Rivers].”

The Jaguars turned the first interception into a 27-yard touchdown drive and a 7-7 tie.

The second interception that counted was a level of Favre-like stubbornness typical of Rivers. He stared down a receiver, thinking he could jam the ball through a small window.

The Jaguars turned that mistake into a 3-yard field goal “drive” and a 27-20 lead with 2:50 left in the game. Needing a touchdown, the Colts lost when they turned the ball over on downs at the Jacksonville 26.

Overall, Rivers completed 78.3% of his passes for 363 yards behind excellent protection from one of the league’s best offensive lines.

Reich was with Rivers in San Diego as quarterbacks coach in 2013 and as the offensive coordinator the next two seasons. He knows the risk vs. reward balancing act, having seen Rivers lead the league in completion percentage (.695) in 2013 and interceptions (18) a year later.

“I love the way Philip plays; I love his aggressive mind-set,” said Reich, who coaches with a similar philosophy. “I think he’s a great decisionmaker. I think he’s an extremely productive player.

“I know people have said there’s more interceptions here and there, but as a coach and ex-quarterback, I just tend to look at those on a case-by-case basis and I think there’s always some risk with some of the reward. The key is balancing that out. We have a lot of trust and confidence in Philip that he’s going to be a great decisionmaker for this team and do a good job of protecting the football.”

Rivers, whose 20 interceptions last year led the league, became the 28th NFL player to throw 200 career interceptions. Of those 28, 14 are in the Hall of Fame, and Drew Brees, No. 15 on the list (236), will be the first year he is eligible.

The top five: Brett Favre (336), George Blanda (277), John Hadl (268), Vinny Testaverde (267) and Fran Tarkenton (266).

Most of the players on the list have at least two things in common: longevity and a fearlessly competitive nature that’s not extinguished by turnovers.

“[Rivers] has elite toughness physically and mentally, a very tough competitor,” Reich said. “And like the other great quarterbacks, he’s a very instinctive playmaker.”

A lot has changed in the nine months since the Vikings forced seven turnovers — four by Rivers — in a 39-10 win at Los Angeles. Rivers’ line now is better, and the Vikings’ defense certainly is worse.

But anything — good, bad or ugly —- can happen Sunday because you never really know what to expect when Rivers drops back to pass.