2 key plays that have helped keep Ohio State undefeated

When most experts and fans broke down the Associated Press' first ever unanimous number one team's schedule, most believed that it would be a cakewalk until Michigan State visited Columbus. Underwhelming quarterback play, inconsistent offensive line execution and the inability to contain mobile quarterbacks forced the reigning national champions to play multiple competitive games well into the fourth quarter.

Here is a deep dive into two key plays that have kept the Buckeyes' aspirations to repeat as national champions alive:

Setting the scene

When: Week 3 vs Northern Illinois

Score: Ohio State 13, Northern Illinois 10

Time: 1:55 left in the third quarter

Down and Distance: 1st-and-ten at the Northern Illinois 45-yard line

Play: Defensive coordinator Chris Ash dials up 'Cover 3 Buzz' to try and create a turnover.

How it happened: 'Cover 3 Buzz' is a variation of Cover 3 which looks like quarters (Cover 4) pre-snap, before the strong safety walks down into the box.

When Northern Illinois' quarterback Drew Hare, who came into the game with a 6:0 TD:INT ratio, made his pre-snap read, he saw strong safety Vonn Bell and free safety Tyvis Powell aligned in a quarters or two-shell look, which he most likely assumed that the Ohio State defense would be in their base Cover 4. Middle linebacker Raekwon McMillan was showing blitz off the edge and it looked like linebacker Darron Lee would be on an island against two Husky wideouts. With Hare believing that the Buckeye secondary was going to drop into quarters, he saw the numbers advantage and assumed that the WR screen should gain good yardage if one could get a chip on Lee.

By the time Hare called the cadence, Bell had made his way into the box and the defense showed that they were in Cover 3, but Hare did not make the adjustment. In Cover 3, the two cornerbacks have their deep third responsibilities and Powell (FS) has deep middle. Lee is positioned up on the line, ready to press and disrupt off the line of scrimmage, but he also has curl and flat responsibilities. Bell is the 'buzz' player, meaning he will be responsible for the middle and the hook area.

By the time Hare made his decision pre-snap, the Buckeye defense was already in position to make a play. Lee's elite play recognition caught the blocking wide receiver off guard and out of position. McMillan's blitz also made Hare believe that if the screen was completed and if Lee was blocked, it would be a big play (thinking Bell was in quarters).

The blocking wide receiver did not lay a finger on Lee, who was actually in better position than the intended receiver, and all he had to do was make the catch.

Lee made the grab, stiff-armed the receiver and essentially clinched the game for the Buckeyes over the upset-minded Northern Illinois Huskies.

Setting the scene

When: Week 5 at Indiana

Score: Indiana 17, Ohio State 13

Time: 1:14 left in the third quarter

Down and Distance: 4th-and-1 at the Ohio State 35-yard line

Play: Urban Meyer trusted his offensive linemen and the most complete running back in the country to execute 'Jet-Motion Power,' to move the chains on a risky fourth down try.

How it happened: it may have looked desperate, going for it on 4th-and-1 on your own 35-yard line, but Urban Meyer wanted to show trust and take advantage of their physical dominance over a less-talented Indiana front seven. He dialed up the power run play, the same play that was unstoppable in the 2014 season.

On 'Jet Motion Power', the jet motion comes from the H-back, Dontre Wilson. He is used as a decoy to force the defense to show the tiniest bit of hesitation when he flies across the line of scrimmage. The left guard and left tackle are supposed to down block, while right guard Pat Elflein pulls around the down blocks to hit the linebacker.  Tight end Nick Vannett will get to the second level on the outside linebacker and Ezekiel Elliott's job is to follow Elflein.

The down blocks are executed perfectly, destroying the interior of the Indiana defensive line. The linebacker (#44) and safety are ready to fill and it looks like it could be a violent collision in the hole.

Elflein did a great job of meeting the linebacker in the hole and kicking outside. It was Elliott versus the safety. If the safety makes the hit behind the first down marker, Indiana has a chance to go up by two scores heading into the fourth quarter.

The safety showed terrible form as he did not break down in the hole to meet Elliott. Elliott put his foot in the ground and made a nice cut, breaking the safety's poor arm tackle attempt.

Nobody is catching Elliott once he gets to full speed.

The gamble paid off.