Arian Foster's numbers speak for themselves.
From 2010 to 2012, the Houston Texans running back rushed for 4,264 yards. He took 41 hand-offs to the house. He was All-Pro three times. Went to three Pro Bowls, too.
Foster is a talented back, no doubt, with soft hands and surprising burst for a man his size. But what truly makes him special is how well he fits in the zone-blocking scheme the Texans have used since 2008, when Texans coach Gary Kubiak hired Alex Gibbs, who coached the offensive line when the Denver Broncos won two Super Bowls in the 1990s. Gibbs is no longer in Houston, but the effective scheme he implemented remains.
There are two categories of zone runs: inside and outside. So what's the difference between the two and how does the zone-blocking scheme work?
"The inside zone is a 'vertical push' play that aims to move the defense backward and have a running back carry the ball forward with a full head of steam to get yards. The outside zone is more about lateral movement. Each blocker first steps to the side rather than forward," Brown, who is also an author, wrote two years ago. "The blockers then try to pin defenders to the inside -- or if they can't do that, drive them to the sideline.
"Sometimes on these plays, the running back runs around the edge on a traditional-looking sweep. More often, the defense is stretched to its limit and the runner hits a crease and then sprints straight toward the end zone. When executed correctly, it's extremely taxing on the defense, as all of their instincts -- aggressiveness to the ball carrier and fast pursuit -- work against them, and linemen without great size or talent can open huge holes through excellent technique and discipline."
While power blocking is all about the linemen kicking the butts of the men they are asked to block, zone blocking relies more on deception, though it also takes a toll on defenders.
Cut blocks are also a key part of the zone-blocking scheme and are something that NFL defenders have complained about cut blocks for years. Remember when the Pittsburgh Steelers accused the Ravens, who use zone blocking at times, of using illegal blocks in 2011?
For five years, fullback Vonta Leach plowed open running lanes for the Texans, most notably serving as the bodyguard for Foster in his breakout 2010 season. He said that the cut blocks -- in which linemen go low to take out defenders -- keep defenders on their toes.
"[The Texans] make the front-side people run and then they cut down the back-side," Leach explained to me Thursday. "Once they cut down the back-side, it creates big holes and big lanes. Even if they don't get the cut back-side, they still have to defend it and the defenders are worried about the cut blocks and give the running back an opportunity to hit the back-side."
This is where Foster and his talented backup, Ben Tate, come in. The Texans coveted them because they have a great feel of when lanes will open up in the scheme and they are quick to make one cut upfield then take off toward the end zone.
"Even though they're a little bit different in style, the thing that really grabs your attention is when these guys make a cut, they can get to full speed faster than most backs," Ravens defensive coordinator Dean Pees said. "They're both very, very talented."
Led by Foster, the Texans ranked in the top 10 in rushing yards in each of the past three seasons. They are third in the NFL this season, averaging 146 rushing yards per game.
Foster has rushed for 136 yards and a touchdown. Tate has rushed for 148 yards on about half as many carries. The Ravens, who allowed 181 rushing yards in last year's blowout loss to the Texans, have been preparing for a steady dose of both.
During his news conference, Pees recalled watching the Broncos, with Kubiak as offensive coordinator and Mike Shanahan as head coach, turn guys like Reuben Droughns, Olandis Gary and Mike Anderson into 1,000-yard rushers. He also mentioned how Shanahan, now coaching the Washington Redskins, made magic last year with sixth-round draft pick Alfred Morris.
"All the sudden some back you've never heard of has got a thousand yards," Pees said, chuckling. "It's kind of the system."