In the second part series of breaking down what worked, and what didn't, we turn the focus on what did work. In 2020, the Ohio State offense is what worked.

RELATED: Read Part One here

Since Ryan Day's arrival, the Buckeye offense has not skipped a beat. In 2020, it was no different and led to much success. Ohio State returned one of the best quarterbacks in the country with Justin Fields, but had questions to answer in the backfield.

Statistically, Ohio State amassed more than 4,155 yards over the course of just eight games. This averages out to be 519 yards per game (262 passing, 256 rushing) and lands them as the No. 7 offense in college football.

Arguably, Ohio State had the most balanced offense in the country, and made the Buckeyes very dangerous.

At any point in the game, defenses could never game plan for specific situations in a game with the balance (other than the 2nd and short deep ball incoming). Ohio State was also able to change personnel quite often, and they were in 12 (one back, two tight ends) personnel as much as they were in 11 (one back, one tight end).

This makes me believe that whoever the Buckeyes have behind center, they will just fine with Day leading the offense. We will take a look as to what Day built his offense around in 2020.

For any offense to be successful, being balanced is fairly important. The Buckeyes averaged 256 rushing yards a game, which is running the ball at a very high level. In 2020, Day based his running game and offense around mid-zone.

This is no surprise, as this was Ohio State's base running play in 2019 as well with J.K Dobbins. When offenses utilize zone running concepts, especially outside and mid zone, it takes quality game reps and time to come to fruition.

With the lack of spring ball, and fall camp, it took time for mid-zone to time up well.

Mid-zone is a NFL staple, as well as outside zone. In Ohio State's case, this is where the running game starts.

Mid-zone is fairly similar to outside zone, but have a few distinct differences. The RB's aiming point is inside leg of the play-side tackle. In a normal outside zone play, the aiming point for the back is the outside leg of the tackle, and the goal is to get the ball outside. With mid-zone, the ball isn't necessarily aiming to get the ball outside. More times than not, the ball hits just inside the tackle (where the aiming point is).

Where mid-zone really hurts teams, is back side. Back side players in a given defense are taught to "sift" and play the backside slow. With mid-zone, offensive lineman are trying to get inside defenders to cut them off from the ball. This. in itself, takes defenders out of the play and makes it easier on lineman.

Outside of mid-zone, Day rarely uses other running schemes consistently. In 2020, the rushing attack featured mid-zone, inside zone, and duo (power without the puller). Outside of these three running schemes, Day does not like to utilize much else.

Gap scheme is just not something he believes in, and something that will never be apart of Ohio States rushing attack.

Mid-zone is a horizontal stretch of the defense, with the end goal of getting the play-side end kicked and the ball getting hit inside of that. This concept puts a bind of box players, as the line of scrimmage moves, and having to use gap integrity. This forces LB's to run and fit the ball in places they are not normally accustomed to.

This is why mid-zone is so hard to defend, and becoming a staple run play in the NFL. These are some of the reasons also that play-action off mid-zone can lead to explosive plays.

Ohio State takes mid-zone one step further than most teams, in that the Buckeyes "slice" the TE backside of mid-zone.

This cuts off backside penetration, and also affects how LB's play their run fit. Defenses usually have their LB's fall back when a TE comes across the formation like they do with sifting on the backside of run plays.

This means that the LB's will walk with the TE post snap to the side he is sifting to. TE's that do this add an extra gap to the sift side, and this helps even numbers with LB's who fall back.

This first example is why mid-zone with a Y-sift really hurts defenses. As the TE comes across, Northwestern's LB's fall back away from the play. This gives Ohio State some room to work with, and helps the offensive lineman climb to their designated spot.

Trey Sermon's aiming point is the inside leg of the tackle, but with the 2i crossing the centers face, Sermon hits it backside.

With Ohio States tendency to run mid-zone with a Y-swift, defenses started slanting towards the run side. This created backside running lanes that Sermon hit many times in 2020. Defenses learned that this run concept has many answers, and it's very hard to stop.

When Ohio State gave Fields an outlet to read a defender and carry out fakes, it also froze backside defenders and created more creases for the running backs.

As you can see, the y-sift again forced the LB's to fall back and give Sermon lanes to run through. This was a great example of where the aiming point is for the back in mid-zone.

Aiming point is for the inside leg of the tackle, and the tackles job is to take the 5 technique where he wants to go. Nine times out of ten, the tackle creates a kick out block and a nice lane to run through.

When Ohio State wasn't hurting teams with mid-zone a change up was to hit inside zone. Inside zone is a downhill running concept that gives the QB the ability to read a defender.

This proved to be an explosive run concept because Fields was always able to hold backside defenders and created huge running lanes. This was the one concept where Fields had the green light to read a defender and pull if need be.

Lastly, Ohio State went to duo often. Duo is power without the puller, and creates double teams at the point of attack. Everyone is blocking down, creating a 1-on-1 with the force player. In this case, it was the walked down safety, and could not make the tackle. Day ran this primarily out of 12 personnel, getting as many guys on double teams as he could.

As many know, this is where Ohio State made its money in 2020.

The passing game came out hot, and never missed a beat. When it comes to Ohio State's passing game, Day uses a NFL approach and uses a variety of concepts.

Day put a lot of Fields' shoulders, and Fields really shined in this system. It paid off as Fields and the passing offense averaged 262 yards a game.

In 2020, Day used the following pass concepts: Y-Cross, 96 (all curls), shallow cross, 4 verticals, flood concepts, snag, spot, shallow and go, mesh. These were to just name a few, as there were many more. The pass concepts that Day used consistently in 2020 was tailored to Fields strengths.

Ohio State operated under a vertical passing game in 2020, rarely using any quick game or screens consistently. Fields has an explosive arm and can put the ball where needed past 20 yards, so Ohio State used his strength.

Putting the ball in the air and stretching defenses vertically also helped improve the running game. Secondary's were solely focused on making sure the deep ball didn't get completed.

Ohio State had many explosive plays that came off Y-Cross in 2020. This was one of Ohio State's better plays that is designed to beat any coverage.

As Ohio state saw a lot of 2 high MOFO defenses, they tagged a post route to attack it. This left corners 1-on-1 with outside leverage, putting them in a bad spot. Ohio State took advantage of this look, and obliterated defenses with it.

Like it was talked about before, Day liked to attack 2 high defenses with this concept for vertical shots. Clemson primarily sat in 2 high vs. Ohio State.

As you will see in this clip, the corner responsible for Chris Olave is in outside leverage. The free safety aligned to Olave's side runs with the cross, and this leaves the outside leveraged corner on an island.

The post is one of the last reads in the progression, as Fields was able to get to it many times.

Versus 1 high structures, Day didn't seem to use the tagged post off Y-Cross.

Here, Nebraska is in a 1 high shell, and they run a basic Y-Cross. One of the things the Ohio State offense utilized well, was having multiple guys run the crossing pattern throughout the season.

In this example, Garrett Wilson is running the cross and gets matched up with the Mike LB.

Ohio State's offense also ran Y-Cross from a variety of formations and personnel groupings.

With this example, Ohio State is in 12 personnel (1 RB, 2 TE's). Nebraska walks down the field safety to the TE, and this leaves the corner 1 on 1 with outside leverage. This again puts the corner 1 on 1 with Wilson.

To make up for the lack of quick passing game, Ohio State used snag as a base quick 3 step game. Snag is a horizontal and vertical stretch on the defense. With a corner, snag, and flare route, it is attacking all levels of the defense.

This was a favorable call for Day when they needed a quick 6-7 yards. Snag puts the flat defender in a bind, as he has to widen with the flare, or sit with the snag route.

On this example, the force player runs with the vertical stem by the TE. This opens space for the snag route to get completed in between the corner and force player. Again, the goal is to attack the defense both horizontally and vertically.

Day is exceptional at running his base concepts from a variety of formations and looks. He will stack release, switch release, motion his WR's to gain leverage on pass defenses.

He does this to protect his base pass concepts so he doesn't put a lot on Fields shoulders. On this example Day stack releases the receivers on snag. The force player widens with the flare route from the back.

Day also went to drive concepts and liked to use them in the red area. This again puts an emphasis on attacking the defense horizontally and vertically. With receivers on the run, this is also good vs man coverage and why it was utilized in the red area.

This is why Drive is great versus man coverage. All receivers on a drive route are on the move and forces defenders to play tight man coverage.

Many times in 2020, Day would run a corner route with an inside receiver which resulted in a lot of scores.

Lastly, Ohio State found much success with play-action flood concepts off of run looks.

Like it has been mentioned before, the Buckeyes had a lot of success running the football. Off play-action looks, Ohio State would run flood concepts to again attack the field horizontally and vertically. Defenses were accounting for the run, and opening up holes in the passing game.

With this play-action flood, Penn State's LB core is so focused on getting to the run, that it can't get out in pass coverage. Simply put, Ohio State used this as its counter to Penn State's successful run game.

With Ohio State having to replace Fields and his skill set, it will be a fun spring and off-season trying to dissect who they want to be.