How Bad Has Andrew Luck Been in 2015?

By just about any measure -- the eye test, the raw numbers, the analytics -- Andrew Luck isn't the same quarterback that he was last year.

Right?

Sure, the Indianapolis Colts' franchise quarterback ranks 13th in the league in passing yards through Sunday of Week 3. But he's got just 5 touchdowns and 7 interceptions on the year, and his adjusted yards per attempt of 4.64 ranks 36th among 38 quarterbacks with at least 30 pass attempts so far.

That's better only than Matt McGloin (4.42) and Jimmy Clausen (3.48).

Yikes.

Last year, for comparison's sake, his adjusted yards per attempt mark of 7.86 ranked 7th among 36 passers with at least 200 attempts. He also threw 40 touchdowns to 16 interceptions. 

No matter how you spin it -- not even with the Colts' comeback win in Week 3 -- Luck isn't the same as he was last year (which wasn't as good as it seems).

What gives?

Luck's Advanced Metrics

Last year, Luck led the NFL in passing touchdowns, and he was second only to Drew Brees and Ben Roethlisberger in passing yards: 4,761 to 4,952 for the co-leaders. Based on those numbers alone, it sure seems like he was a fantastic NFL passer.

Is this enough foreshadowing for you?

According to our Net Expected Points (NEP) metrics, which compares a player to expectation-level performance, Luck wasn't quite as elite as those types of numbers suggest.

NEP, if you're new, is our signature metric for measuring performance. A 15-yard pass completion will look better than a 5-yard gain in just about every box score measure, but if the 15-yarder leads to a punt and the 5-yarder leads to a first down, then one is clearly a more important football play than the other. NEP accounts for the changes in expected scoring that occur on each play.

So, based on Passing NEP, Luck added 110.33 points above expectation-level with his 643 drop backs last season. That ranked seventh in the NFL. Among 37 passers with at least 200 drop backs last year, Luck's Passing NEP per drop back (0.17) ranked just inside the top 10 at 9th. Not so great as his raw numbers indicate but certainly not bad.

The real issue -- that didn't show in Luck's standard stats -- was Luck's Success Rate, the percentage of drop backs that led to NEP gains for the Colts. Luck's mark of 47.59% ranked 17th in that group of passers.

Of course, only 9 quarterbacks topped a 105 Passing NEP score last year (Aaron Rodgers, Peyton Manning, Roethlisberger, Tony Romo, Tom Brady, Brees, Luck, Matt Ryan, and Philip Rivers), and only 10 posted a score higher than 66.

In that regard, Luck is still in a pretty nice group, but that Success Rate is troublesome, and we should have seen this coming.

To go a little deeper, of that group of 9 passers with a 105-plus Passing NEP in 2014, only one ranked outside the top 9 in Success Rate. We already know who that is, and he ranked 17th. The rest of the group had a rate better than 50.00%, and only one other quarterback (Ryan Tannehill) maintained that level of success on at least 200 drop backs.

This suggests a significant reliance on big plays from Luck to boost his Passing NEP. On a per-drop back basis, Luck still graded out as a top-10 passer, but his wildly low Success Rate put him in a different category of passers than his steady-earning elite peers.

And if you're pondering about Luck's rushing ability, then just know that he ranked only 8th in Total NEP (114.02). If you've got a really good memory, that number isn't much higher than Luck's Passing NEP (110.33). That's because his Rushing NEP (3.68) ranked just 20th among those 37 quarterbacks with at least 200 drop backs.

We're talking lower than Josh McCown (6.14) and Eli Manning (5.55).

Luck in 2015

Of course, it's not just told-you-so analysis now that Luck has been struggling out of the gate. Rather, it's important to know that Luck just wasn't as analytically impressive as other passers in the league last season, so we need to keep that in mind when breaking down his current metrics for the young season.

Entering Week 3, Luck's Passing NEP (4.96) ranked him 19th among 35 passers with at least 10 drop backs. On a per-play basis Luck (0.06) ranked 21st. And that Success Rate (42.05%) ranked him 26th.

Luck's Week 3 woes were somewhat forgiven because the Colts wound up winning, but that doesn't reflect well in his metrics. Now, NEP doesn't factor in "heart," but according to our initial tallies on numberFire Live, Luck finished the game with a Passing NEP of 1.60. His Rushing NEP was -1.06, so he was good for about half a point to the team's expected point total.

There are rumors that Luck is playing hurt, so perhaps that's what's ailing him so drastically early in 2015.

But through three games, Luck is being outplayed by journeymen quarterbacks, and the Colts are struggling to put points on the board with the ease that they showed last year when they ranked ninth in the league in Adjusted NEP per play.

Something has to give one way or the other: either Luck regresses toward being to the prolific-but-inefficient player he was last season or there are going to be bigger question marks about what once seemed like one of the surest bets in the NFL.