It's a far too common sight for Colts fans: quarterback Andrew Luck, the face of the franchise and the main reason why the team has been in the playoffs the last three years, on the ground after getting hit. Whether he gets the throw off before (or as) he gets hit or whether he gets sacked, there's no doubt to people who watch the Colts play that Luck is on the ground too much.

In fact, according to Football Outsiders' Scott Kacsmar, no quarterback has been knocked down more than Andrew Luck has been over the last three seasons, with Luck leading the league in that category for three years in a row.

QB knockdowns (hits + sacks) 2012 leader - Andrew Luck (122) 2013 leader - Andrew Luck (115) 2014 leader - Andrew Luck (115) — Scott Kacsmar (@FO_ScottKacsmar) May 18, 2015

The team's offensive line has been a major concern ever since Luck arrived in Indy (and well before that, also), but it hasn't been because of a lack of effort from general manager Ryan Grigson. If you look at the projected starting offensive line for the Colts in 2015, all but one of them were brought in by Grigson, with the lone outlier being left tackle Anthony Castonzo, who had a terrific season in 2014 and is clearly the team's best lineman. Jack Mewhort was drafted in the second round last year. Khaled Holmes was drafted in the fourth round of the 2013 draft. Todd Herremans was signed as a free agent this offseason. And Gosder Cherilus was signed as a free agent in the 2013 offseason. Furthermore, Grigson has signed Donald Thomas in free agency, drafted Hugh Thornton in the third round of the 2013 draft, and re-signed Joe Reitz this offseason, along with other moves. You could make the legitimate case that the line has seen marginal improvement in each of Luck's three seasons, but the bottom line is that the line still hasn't been great. And while this year's unit clearly looks to be the best one yet in the Andrew Luck era, it likely still won't be great.

But let's also realize that it's not all on the offensive line, and I think this tweet from Kacsmar a few days ago is absolutely spot-on:

<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Luck can manage behind that OL. Rarely do I ever watch a Colts loss and think "that was on the line."</p>— Scott Kacsmar (@FO_ScottKacsmar) <a href="https://twitter.com/FO_ScottKacsmar/status/600211874500739073">May 18, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>

The number of hits that Andrew Luck takes will seem higher than some others because of the volume of throws that the Colts attempt, as well as the style of play that the quarterback utilizes. He moves around and isn't afraid to take a hit, sometimes resulting in him taking more hits than necessary.

The bottom line is that Andrew Luck has been hit - a lot - in his first three years in the league, and considering how important he is to the Colts' franchise, that's something that needs to change moving forward. He's an incredibly tough player and is able to take a lot of hits, but they add up over time and it'd be better not to test just how tough he actually is. That's why the Colts continue to try to improve their offensive line, and hopefully this year's unit works out. There are still question marks (namely at the center position and about Gosder Cherilus' health), but the Colts look to have the best line they've had in Luck's time yet. Of course, considering that he's been knocked down than any other quarterback in each of the last three years, that might not be saying a whole lot.