Conventional wisdom holds that your left tackle is the most important position along the offensive line. It's certainly the highest paid, and one of the hardest to fill. The mix of size, agility, power and quickness is tough to find. The Dallas Cowboys have found their man in Tyron Smith. The reason left tackles are so important lies in two interconnected ideas. One, it's tougher for quarterbacks to see the rush from their blindside and since most quarterbacks are right-handed, their blindside is to the left. That leads to the second part, defenses put their best pass rusher on that side to take advantage of the blindside. Thus, your left tackle is the man who must defend your quarterback against the blindside sack.

The NFL is an ever-changing game, and one of the changes we're seeing more and more is defenses moving around their best pass rusher in hopes of getting a better matchup. More and more, those elite pass rushers are lining up against right tackles. And they are finding success. That would put a lot of pressure on the Cowboys right tackle, Doug Free.

The evidence is provided in this article from SB Nation.

Quarterbacks used to take most of their snaps under center, dropping back five or seven steps, and then releasing the ball, but the game's gotten a lot faster. A quarterback's progression has changed. They're taking more snaps out of the shotgun formation, giving them time and opportunity to survey the whole field and making blindside protection less of a priority than balanced protection on both sides.

With faster reads and faster releases becoming the norm, the need is for pass rushers to beat their man as quickly as possible. If you can get a mismatch at right tackle, you take it.

But even more evidence is provided by data.

Back in 2012, Pro Football Focus looked extensively at how quarterback performance changed under pressure from each side, and they found that quarterbacks generally perform worse when pressure comes from the right side. Intuitively, it would seem that quarterbacks would be better prepared to adjust when pressure isn't coming from their blind side, but the numbers don't support that. Based on their 2012 data, pressure from the right side resulted in sacks slightly more often than pressure from the left side. Pressure from the right side ended in a sack 17.3 percent of the time, while pressure from the left culminated in sacks 15.5 percent of the time.

Some of that discrepancy can be accounted for by left tackles who are simply better, and allow pressure but manage to do enough in blocking a defender to save the sack. But the similarity in numbers shows that pressure from either direction is formidable.

And recently, the numbers corroborate the sack numbers coming from the left side of the defense, the right side of the offense.

Defenses do scheme to attack the weakness along the offensive line, pairing the defense's most dominant pass rusher against the right tackle. Players like [Von] Miller, Justin Houston and Khalil Mack rush from that side of the formation a majority of the time. Houston led the league in sacks in 2014 with 22, and Mack racked up 15 sacks last year in his second season with the Oakland Raiders.

We know that Tyron Smith is the most-talented left tackle in the league (sorry Joe Thomas). But is Doug Free the key to keeping Tony Romo healthy in 2016?