Big Ten 4th Down Calculator: Championship Edition

The College Football Playoff technically doesn't start until December 31st, but in reality it started Saturday night in Indianapolis. The winner of the Big Ten Championship Game was in the playoff, while the loser was out. The stakes couldn't have been higher. So the competitors need to make sure they gain every advantage they can. And that's where 4th down decisions come in. With a lot of coaches making sub-optimal 4th down decisions, your team could gain an edge if you use statistics to make the correct decision. And that edge can be the difference between a playoff appearance and an exhibition game.

So, how did Iowa and Michigan State do?

A few quick things before we begin. My 4th down calculator is based on a regression model that predicts a team's expected points, and takes into account home field advantage. However, this game was played at a neutral site. So I used an adjusted model that doesn't use home field advantage. Also, for the average net yards on a punt, I used each team's season average (as opposed to the Big Ten average that I've used previously).

And, as always, the calculator isn’t meant to provide decisions written in stone. In hypothesis testing, it’s important to understand the difference between statistical and practical significance. A test that finds a statistically significant result doesn’t imply that the result has practical consequences. The people testing the hypothesis should use their specialized knowledge to determine whether the difference is practically significant. Apply the same line of thought to the 4th down calculator. If you're the coach, you should also consider other factors—but the 4th down calculator still provides a great starting point for making the decision.

Now let's break down the game.

Michigan State 16 - Iowa 13

Instead of summarizing the 4th down decisions, I'm going to break down each one. After all, we only have one game to talk about.

4th Down Decisions in the First Half

The score at halftime was 6-3. On the surface, this might make you think this was a boring game. But you would be incorrect, as the first half featured only 4 punts. And if the coaches had made some better 4th down decisions, we would have had even fewer punts!

Michigan State opened the 4th down decision making with a 4th and goal at the 5. The general consensus is that you have to take the field goal, and in this instance the calculator agrees...barely. You'll see that the expected points for going for it are about the same as kicking a field goal. This is because even if Michigan State fails on 4th down (which they would do about 68% of the time), Iowa would start with the ball deep in their own territory. Any time a team punts, the best-case scenario (outside of a turnover) is that they down the punt inside the 5 yard line. In this case, the worst-case scenario (outside of a turnover) is that the opponent starts inside their own 5 yard line. There is nothing wrong with Michigan State kicking a field goal here, but in general teams should be much more aggressive inside the five yard line on 4th down.

Having said that, there is a big problem with Iowa kicking on the next 4th down decision. They punted on a 4th and 1 at midfield. And the worst part is that it wasn't even a full yard. On 3rd and 1 they tried a quarterback sneak that just came up inches short. This season Iowa had one of the best rushing offenses in the Big Ten. To punt on 4th and inches is just insane. Following the punt, Iowa did get an interception that led to a field goal. But imagine if they converted the 4th down, scored points on the drive, and then still got the interception on defense. In a game where points were hard to come by, you can't just willingly leave them on the field.

Iowa left more points on the table early in the 2nd quarter. But this time it was the players' fault, not the coaches. On a 4th and 4 from the Michigan State 20 yard line, Iowa correctly decided to go for it instead of kicking a field goal. But their tight end moved early, and the false start penalty moved them back 5 yards. Now faced with a 4th and 9, Iowa correctly attempted a field goal. They made the kick, but we're left to wonder what might have been if they converted the 4th down and scored a touchdown on the possession.

The next possession, Michigan State faced a 4th and 15 at the Iowa 34. This is a spot on the field where Michigan State has actually been more aggressive than the calculator suggests. This year, they've had 6 instances where they've had a 4th and 6 or longer between their opponent's 25 and 34 yard line. In all 6 cases, the calculator suggested kicking a field goal. But Michigan State actually went for it 4 times. And the 4th down distance in those 4 cases were 6, 8, 8, and 10 (they kicked a field goal on a 4th and 8 and a 4th and 12). This shows that Michigan State really doesn't trust their field goal kicker from longer distances. If the 4th down distance was just a little shorter, I'm almost certain Michigan State would have went for it here. But 15 yards is just too hard to convert, so they (correctly) kicked a field goal. But as if to justify Michigan State's decisions earlier in the season, Spartan kicker Michael Geiger missed the kick. 

Believe it or not, Michigan State has had only two 4th and 1s this season (although this doesn't include every 4th quarter). They've correctly gone for it both times, but it helps that they were in opponent territory on both occasions. Late in the 2nd quarter, Michigan State punted on a 4th and 1 from their own 29. Now there was only 1:49 left in the half. So this decision isn't quite as bad as usual, since Michigan State may not have had enough time for a full drive anyway. But it still gave Iowa one more opportunity to score, and half of the reason for going for it on 4th and 1 is limiting the opportunities your opponent has to score. Luckily for the Spartans, the punt netted 57 yards, and neither team scored before halftime.

4th Down Decisions in the 3rd Quarter

Michigan State had an opportunity to take the game over in the 3rd quarter. They did go from being down 3 to being up by 3, but they passed on opportunities to make that lead even larger. The first bad decision was a punt on 4th and 5 from the Iowa 39 yard line. The difference in expected points is only 0.12, so on paper the decision to punt doesn't seem like a terrible one. But really, what is the down side of going for it? The other team might get the ball in their own territory? That's going to to happen if you punt too! Michigan State should have went for it here.

Remember how I said Michigan State has been passing on long field goals and going for it, even on longer 4th down distances? Well, that makes their decision at the end of the 3rd quarter even more confusing. They decided to kick a 47 yard field goal on 4th and 4 from the Iowa 29. Michigan State went for it in this spot on 4th and 10 earlier this season. With the game tied, you might argue that they should kick the field goal to take the lead. Except 47 yard field goals are missed all the time, and Michigan State already missed a long field goal earlier in the game.

And you know what is better than a 3 point lead? A 7 point lead!

Luckily for Michigan State, they did make the field goal. And the Spartans took a 9-6 lead into the 4th quarter.

4th Down Decisions in the 4th Quarter

In the 3rd quarter, Iowa gained a grand total of -7 yards (including penalties) against Michigan State. The Hawkeyes hadn't even gained a first down since 5 minutes remained in the 2nd quarter. And to make matters worse, they had a 2nd and 20 at their own 15 yard line. Even though Michigan State left points on the table in the 3rd quarter, you probably thought they were in good shape with a 3 point lead going into the final 15 minutes of the game. 

You thought wrong.

The first play of the 4th quarter was a 85 yard touchdown pass for Iowa. That's why it's so important to maximize your points in the first three quarters: If the score is close, it only takes one play to completely change the dynamic of the game. If Michigan State had been up by multiple scores, they would still be in good shape. But now with Iowa being up by 4 points, they were more likely to lose the game, especially when they had to punt on a 4th and 9.

Everybody is going to remember the 4th and 2 that Michigan State converted at the end of the game. But Iowa had a big decision on their own 4th and 2 the drive before. Instead of going for it, they decided to take a delay of game penalty and punt. My first reaction was that this was a terrible decision. I was sure the statistics would heavily favor going for it. But surprisingly, the numbers are just about even. They slightly favor going for it, but the difference is 0.3%, so really, either decision is fine. And with Iowa having a strong defense and Michigan State quarterback Connor Cook appearing to possibly be hurt, there is nothing wrong with the decision to punt. Having said that, I think there is a more general reason most coaches will opt to punt in this situation.

Iowa kicked and Michigan State scored the game-winning touchdown on the next possession. Did you hear any post game analysis about how Iowa should have gone for it ? How they should have relied on their strong running game to put the game away? Of course not. There was no second guessing the punt, even though it directly cost Iowa the game. Now imagine that Iowa had gone for it, failed, and Michigan State won the game. People would be second guessing that decision left and right. I find it crazy how we never associate the decision to punt with costing a team a game, but we do it with 4th down decisions all the time. Even when it's the correct decision!

Speaking of the correct decision, there is no doubt Michigan State should have went for it on 4th and 2 at the end of the game. You're only 5 yards from taking the lead, and there is no guarantee you get the ball back if you kick a field goal. Deciding to kick would have lowered their win probability by almost 20%. Kicking a field goal here would have by far been the worst coaching decision made in the Big Ten this year. Luckily for Michigan State, they left their conservative decision making in the 3rd quarter, and went for it.

And if they're going to upset Alabama in the College Football Playoff, they're going to need to do more of the same.

End of the Season Summary

Here is a breakdown of all the 4th downs (through the first 3 quarters) in the Big Ten this year. I'm using just the first 3 quarters since many of the games this year were blowouts in the 4th quarter. You can get every 4th down decision that I tracked this season here.

Team Summary

Northwestern had 4th and 1 seven different times this season. They went for it only two times, punting 3 times and kicking two field goals. And they had 10 more 4th down distances of 2 or 3 yards, and kicked every time. Ironically, they did go for a 4th and 7 from their opponents 29 yard line when the calculator suggested a field goal. Oh, and of course the very next game they kicked a field goal on 4th and 1 from their opponents 25. Go for it on 4th and 7, and then kick a field goal on 4th and 1. There is Northwestern's 4th down decision making this season in a nutshell.

But you might ask what the point is if Northwestern was still able to go 10-2 despite their 4th down decision making? Well, Northwestern was 5-0 in games decided by 1 possession this season. By leaving points on the table, they kept playing in close games. And in the long run, your record in 1-possession games is going to be 0.500. So they aren't as good as their record would indicate (just look at the fact that they are 9 point underdogs to 8-4 Tennessee in their bowl game). And if Northwestern continues to make sub-optimal 4th down decisions next year, I sure wouldn't bet on them to repeat their success of this year.

 Where Can Coaches Improve?

Let's take a look at where coaches could improve their 4th down decision making. First, let's look at how often they agreed and disagreed with the calculator.

When the calculator suggested a field goal, coaches did kick the field goal about 80% of the time. And honestly, the other 20% probably had more to do with my model overestimating a kicker's accuracy from longer distances than coaches making bad decisions. I used game data to calculate the probability of a kicker making a field goal. But for longer distances, a coach is only going to attempt a field if he thinks his kicker has the range. So for kickers without a strong leg, my model likely overestimates their chance of making a long field goal, and thus the coach is correct to go for it or punt instead of listening to the calculator.

And coaches are right on board when the calculator suggests punting. So that only leaves one option...going for it!

If you've been following along with me all season, I bet you never saw this coming...but coaches are being too conservative on 4th down. They are punting when they should be going for it about half of the time! That's 89 times when they could have tried to keep possession and score more points, but instead willingly gave the other team the ball.

But I know what most coaches are probably thinking. "This just based on some mathematical jargon—it doesn't really apply to the real world." Well, here are some real-world results. I took every single 4th and short (1 or 2 yards to go) and looked at what the next score was for each coaching decision.

If you go for it on 4th down deep in your own territory, the fear is that the other team will have an easy score if you fail. But look at what happened to teams who punted this season. The 14 times the team punted on 4th and 1 or 2 inside their own 25 yard line, their opponent was more likely to be the next team to score, to the tune of 4.1 points! Even with a punt, the other team scores next most of the time, anyway! So what do you have to lose by going for it?

Things get a little more reasonable outside the 25 yard line. But the 8 teams who went for it between their own 25 and midfield were justly rewarded, outscoring their punting counterparts by a point and a half! And once you cross midfield, going for it remains the best option. Teams that went for it between midfield and their opponent's 25 scored more on average than the teams that tried to "pin their opponent deep." And LOL Northwestern for being the one team that attempted a field goal.

As for the people who claim you have to "take the points" once you're in easy field goal position, well...teams who went for it scored more points than the teams who kicked the field goal. Take the points, indeed!

But on a positive note, most coaches are going for it on 4th and 1 and 2 once they get past midfield. That's a positive! But should they be even more aggressive than that? Coaches are good at going for it on 4th and 1 or 2, but once they get past the 10 yard line they should also be going for it on 4th and 3 and 4th and 4. So let's look at what decisions they made inside the 10.

Unfortunately we have some small samples sizes here, but the real-life outcomes still support what the calculator suggests. Teams who went for it on 4th and 1 and 4th and 2 scored over two more points than teams who kicked a field goal. Unfortunately, teams stopped being aggressive on 4th and 3 and 4th and 4. Not a single coach decided to go for it, as they all went with "taking the points." Except you'd actually be taking more points if you went for it!

You might be wondering how teams who kicked a field goal on 4th and 5 to 4th and 10 actually scored more than 3 points on average. There were two cases where a team missed a field goal. Oh no! That's terrible, right? Except they were able to get the ball back and scored a touchdown on their next drive. And that's with the other team starting at the 20 after the missed field goal. If you fail on 4th down, they'll start even closer to their own end zone. All the more reason to be aggressive on 4th down inside the 10!

And if you're still not convinced after all that math, consider an intangible benefit of being aggressive on 4th down. Imagine you're a coach recruiting a star running back or star quarterback. You tell him that every other coach is going to punt on 4th and 1 in their own territory and kick a field goal on 4th and goal from the 3. But us, we're going to go for it. And you know what that means for you? More yards. More touchdowns. More impressive stats. And if we fail on 4th down, nobody is going to blame you. When the Heisman voters look at statistics, they don't care about what percentage of 4th downs a quarterback converts. What they care about is yards and touchdowns. And we're going to give you more opportunities to gain yards and score touchdowns than any other team.

So that will wrap things up for the Big Ten 4th down calculator this year. Enjoy the bowl season, and until next year always remember that...

Kicking is for quitters!