A former head coach has replaced a new head coach who also used to be a head coach.

This is the NFLâ€™s coaching carousel.

The Baltimore Ravens announced that they would be bringing on former Texans head coach Gary Kubiak to fill their offensive coordinating void â€“ a position that opened with past offensive coordinator Jim Caldwell taking the head coaching gig in Detroit.

Itâ€™s now Kubiakâ€™s job to turn around an offense that ranked 27th in the league according to numberFire metrics. Can he do it? Well, letâ€™s, of course, see what the numbers say.

Kubiak and the Zone Blocking Scheme

I always like digging into a coachâ€™s history, not only because itâ€™s a nice introduction as to who that coach is, but it allows me to refresh my own memory. And, at times, it forces me to go a little deeper on particular topics.

One of those topics with Kubiak is his love for the zone blocking scheme, something he learned while coordinating Denver's offense under Mike Shanahan and company (Alex Gibbs) from 1995 to 2005. During that time with Kubiak as offensive coordinator, running backs like Olandis Gary, Clinton Portis, Reuben Droughns and Mike Anderson were rushing for over 1,000 yards regularly. And, of course, we canâ€™t dismiss the fact that, under Kubiak, Terrell Davis rushed for over 2,000 yards in 1998.

Kubiak's offense in Denver often times had a pass-to-run ratio that was less than 1.00, something only two teams â€“ Seattle and San Francisco â€“ had in 2013. Though it was certainly more common to run the ball at a higher rate back then, only a handful of teams (six in 2003, for example) actually got their ratio under 1.00.

Over Kubiakâ€™s final three years with Denver, just before he became head coach in Houston, the team put together the 5th-, 11th- and 4th-ranked offenses in the league according to our Net Expected Points (NEP) data, led by a 0.94 pass-to-run ratio. While the rush offense was ranked 17th in 2004, the 2003 and 2005 versions ranked 3rd and 2nd in the league respectively.

Kubiak in Houston

Coach Kubiak took his zone blocking scheme talents with him to Houston, and we saw similar results. Steve Slaton broke out as a stud running back in 2008, rushing for 1,282 yards and nine scores during his rookie season. He soon fell off the face of the Earth, allowing now perennial Pro Bowl running back Arian Foster to take over in Houston. While being coached by Kubiak in Houston, Foster had two seasons with more than 1,200 rushing yards, three with double-digit touchdowns and three with 40 or more receptions.

Keep in mind, Kubiak entered Houston a season after they went 2-14, so itâ€™s more than likely the personnel wasnâ€™t there when he first arrived. Itâ€™s not exactly his fault that David Carr was his signal-caller, while Ron Dayne was lining up in the backfield.

Kubiak added four wins to the Texans when he got there, taking the 2006 squad to a 6-10 record. The team then went 8-8 in 2007 and 2008 before getting over .500 in 2009. Though the team hit a bump in 2010, Kubiak was able to successfully take the Texans to the playoffs in 2011 and 2012, their first appearances as a franchise.

While the defense played a major role in those playoff appearances, thanks to Wade Phillips, the offenses in Houston, despite never having a true franchise quarterback, were always competitive. Below is a chart showing their rankings in total, pass and rush offense through the years, as well as their pass-to-run ratio, under Kubiak:

Total Pass Rush Pass-to-Run Ratio 2006 19th 18th 17th 1.22 2007 11th 14th 14th 1.32 2008 14th 15th 10th 1.36 2009 11th 7th 29th 1.46 2010 2nd 7th 3rd 1.43 2011 10th 10th 6th 0.91 2012 14th 11th 21th 1.15 2013 30th 30th 26th 1.63

Keep in mind that the rankings above reflect our Adjusted Net Expected Points, Adjusted Passing Net Expected Points and our Adjusted Rushing Net Expected Points metrics. In essence, these NEP numbers are adjusted for strength schedule, making it easier to compare one team to another.

As you can see, a typical Kubiak offense ranked close to 10th in the league, while his 2010 squad finished second. That was Arian Fosterâ€™s breakout 1,616-yard, 16-touchdown campaign. Funny enough, because the Texans defense was so bad (dead last in the league according to our metrics), the team went 6-10.

From a rushing efficiency perspective, Kubiakâ€™s Texans were kind of all over the place. They finished 29th in 2009 thanks to the aforementioned Steve Slaton falling off the face of the Earth, but hit high marks with Arian Foster. They were, however, unable to move higher than 21st over Kubiakâ€™s final two seasons.

I should note that itâ€™s difficult to have a highly efficient rushing offense with a statue under center, especially in recent NFL seasons. For the majority of Kubiakâ€™s time in Houston, Matt Schaub was the quarterback, and if youâ€™ve watched Matt Schaub run, you know there are people at your local L.A. Fitness who can do it faster than he can.

But speaking of Schaub, it wouldnâ€™t be right for me to ignore what Kubiak was able to do with his passing offenses while in Houston. This is something that may go under the radar with his hire in Baltimore, as his zone blocking scheming will take precedence in analyses. However, if you look at his teamâ€™s passing games, you could make the argument that heâ€™s more effective at coaching that facet than the running one on offense.

This really isnâ€™t surprising, as Kubiak was the 49ers quarterbacks coach in 1994, and took on the role while being offensive coordinator in Denver.

In Houston, the worst passing offense that Kubiak coached happened this year (obviously), but up until this season, he never coached a passing offense that ranked worse than 18th in overall effectiveness. Moreover, that season was his first with the team, and David freaking Carr was his quarterback.

The team brought in Matt Schaub in 2007, and Houstonâ€™s offense never ranked worse than 14th through the air (again, outside of 2013). And through the years, Matt Schaub, who is probably now incorrectly viewed as a bad NFL quarterback due to this season, had just one year (not counting this season) with a negative Passing NEP score. That happened in 2007, his first year with the team, and his score was barely under expectation at -4.54.

Schaub has always been an underrated passer. I think a lot of this has to do with Kubiakâ€™s tendency to run the ball - you can see those pass-to-run ratios above, which would rarely hit the top half of the league. But with Kubiak in Houston, Schaub had four straight seasons of incredibly good quarterback play, never dipping below 74.28 Passing Net Expected Points. To give you some context, thatâ€™s nearly identical to Russell Wilsonâ€™s passing production in 2013.

So while everyone will be excited with what Kubiak can do to a poor Ravens rushing attack, letâ€™s not forget that heâ€™s a quarterback guy.

Can Kubiak Refine the Ravens?

Baltimoreâ€™s offense was borderline dreadful this season, and any Ravens fan would back that statement up, Iâ€™m sure. The offensive line was easily one of the worst (if not the worst) in the entire NFL, and after winning Super Bowl MVP, Joe Flacco put together his worst season as a starter since his rookie year, according to NEP.

The Ravens also had the worst rushing attack in the entire NFL this year, playing over 52 points below expectation. By no surprise, running backs Bernard Pierce and Ray Rice, after a fantastic Super Bowl run, finished in the bottom two among all running backs in Rushing Net Expected Points.

The key piece to their Super Bowl run a year ago â€“ a cohesive offensive line â€“ was gone in 2013.

Many will point to Juan Castillo, the Ravens â€œrun game coordinatorâ€ (thatâ€™s a thing), as the reason why the running game failed. The team tweaked some of their zone runs, which seemingly created a lot of offensive line confusion.

But itâ€™s not as though the Ravens had never used a zone blocking scheme â€“ or ran zone runs â€“ in the past. Itâ€™s not like the zone blocking scheme was the reason for the Ravens lack of success.

Thatâ€™s why I donâ€™t think itâ€™s fair to assume that a zone blocking guy like Kubiak coming to town will yield the same results. Weâ€™ve seen what he can do with running games in the past, and with a healthier Ray Rice (remember, he had hip issues this year), the Ravens have a shot to instantly get back to their running ways.

Perhaps personnel changes will be in store, but letâ€™s not imagine this rushing attack as the worst entering the 2014 season.

And letâ€™s also not forget that Joe Flacco wasnâ€™t good this year. With more experience at receiver and a healthy Dennis Pitta, Flacco should be able to bounce back and be much more efficient under Kubiak. In essence, this is a situation a lot like what Kubiak helped build in Houston.

So was Kubiak the right hire? Of course. The Ravens are a smart organization and know what theyâ€™re doing. I fully expect the teamâ€™s offense to improve next season under the former Texans head coach, and wouldnâ€™t be surprised if Kubiak's name is mentioned as a head coaching candidate in 2015.