What didn't Brian Kelly see in Ian Book?

Notre Dame has found a rhythm, a flow and a path to a College Football Playoff berth -- not to mention a quarterback -- almost despite the coach who inserted him as starter last week.

It's clear Book, the Irish's junior, is the best thing to happen to Notre Dame at the position since the guy he replaced. That would be senior Brandon Wimbush.

Book threw four touchdown passes in a three-touchdown win over Stanford that has to be causing Domers to ask: What took so long?

In a 56-27 win at Wake Forest last week, Book rushed for three touchdowns and threw for two more. Since starting the Citrus Bowl last season, Book has completed almost 75 percent of his passes. He has proven himself to be the better thrower and maybe the better leader. So, what took Kelly so long?

In the run up to Saturday's 38-17 win over the Cardinal, Kelly was promising nothing. Never mind Book was coming off a 325-yard, two-touchdown game against the Demon Deacons.

"We'll see how it goes each week," Kelly said.

Uh, Brian, it looks like the rest of your weeks are filled with Book. The Irish seem to rally around him. Book was the constant Saturday completing 24-of-33 passes for 278 yards and four touchdowns.   

Worse than that -- for Kelly -- Book hadn't appeared in the first two games. What is it about Kelly and choosing quarterbacks? Remember two years ago when Malik Zaire and DeShone Kizer were sharing time?

There should be no sharing going forward. Kelly has found his man. We knew that, on his best day, Wimbush was going to have to be nursed along as a passer. On his worst day, well, your starting quarterback shouldn't have to be nursed.

Book has provided a spark that wasn't there offensively. Now, we pause at this point in the season to write the Irish-as-playoff contender story.

Book is allowing us to write it. Changing quarterbacks changed the team's outlook. Book is a rangy kid from California. Last year, he became the first Notre Dame quarterback to win his first start on the road since 1995.

With him -- and without him -- Notre Dame is 5-0 for the third time since 2012.

Six years ago, the Irish went undefeated, getting to the BCS Championship Game before being blown out by Alabama. Two years, later the Irish started 6-0 before finishing 2-5. Why is this season different? We're not sure it is, except that after Stanford the schedule starts to open up.

Right now, there are no currently-ranked teams left on the schedule. A trip to Virginia Tech next week looks dangerous except that the Hokies are winning with backup quarterback Ryan Willis at the moment. After that, the only true road games are at Navy and USC.

Yeah, we're looking ahead because that's what sportswriters and Domers do.

Tailback Dexter Williams returned from a four-game suspension to rush for 161 yards and a touchdown. Notre Dame's defense is good enough to hold it in each game. Stanford had given up five sacks in the first four games. K.J. Costello was sacked five times on Saturday.

In case the Irish need more good news: Notre Dame suddenly has better quarterback depth than Clemson.

Wimbush isn't terrible. He just isn't complete. In the opener against Michigan, he completed 12 of 22 for 170 yards. The legs that set him apart ran 19 times for 59 yards.

Book sees the whole field. On the fourth-quarter insurance pass that clinched it, Book threw a swing pass to Miles Boykin. Blocks from Chris Finke and Chase Claypool were waiting on the perimeter.

"We'll see how it goes each week?" Since Book stepped in, Notre Dame has scored 94 points in two games.

The Irish have their quarterback for the rest of the season. Book it.