## Win Probability Calculator Upgrade - New OT Rules

After the MIN-GB overtime game Sunday, you may have stopped by the Win Probability Calculator tool to see what GB should have done on 4th down on the goal line on their first possession. As luck would have it, I rolled out a big upgrade to the calculator just the night before that incorporates the three various game states in overtime.

Under the 'Period' input, there are the 4 quarters, plus 3 overtime states, corresponding to:

-'First possession', in which a team can score a TD to win or a FG to begin...
-'Down by three', in which a team has all 4 downs to move down the field to win with a TD or match the FG to begin...
-'Sudden death', which begins upon any change of possession with a tie score.

The previous version of the calculator still relied on the old pure-sudden-death overtime format. With so few examples to test against, I'm sure there are a few bugs or discontinuities waiting to surprise us, so please note any discrepancies in the comments here. But remember that not all unexpected results are errors--The new format does have its quirks.

The new overtime model has already been working for the WP graphs and team/player stats. Soon I'll roll it out for the 4th Down Calculator too. And more big upgrades to the WP calculator tool are on their way.

### 9 Responses to “Win Probability Calculator Upgrade - New OT Rules”

1. Anonymous says:

There seems to be a problem with the OT calculations. Let 's take the MN-GB game situation - if GB goes for it and fails - as example:

Score Diff:0
Period: SD
Field Position: Own 2
Down: 1
To Go: 10
Win Probability: 0.24

Now, if you just change the Period to "OT1st", the Win Probability jumps up to 0.49.
That can't be correct. SD is always better than OT1st for the team with the ball. The only difference is that they can lose or tie if they score a FG in their first drive.

2. James says:

Anon, that's not correct. When the team with the ball is on their own two yard line the defending team is much more likely to score next than the offense.

3. Larry Maistros says:

These updates are wonderful! It's amazing you were able to do them with almost zero data from games played under the new OT format.
Looking forward to the 4th down calculator update.
Some more suggestions:
On the live WP graphs, if it is a 4th down situation, automatically display the 4th down calculator results off to the side.
also an option to see just the WP graph for the one game i am interested in would be nice, instead of the graphs for all games.
On the 4th down calculator, instead of having line of scrimmage and yards to go as inputs, have yard line first down marker is at and yards to go as inputs, that way if user is entering various potential upcoming 4th down scenarios on 3rd down, or on 2nd down, or even on 1rst down, only 1 input has to be changed instead of 2. Of course time remaining would change throughout that series of downs, but the user could project the time likely to be remaining on 4th down and input that, time is often the least critical factor anyway. To take it a step further, it would be great if one could just enter yard line first down marker is at and get multiple result displayed all on one page for various yards to go on the upcoming fourth down. In other words, results displayed for a potential upcoming 4th and 1, 4th and 2, etc., depending how many you want to cram onto one page. (I say put a lot of them, I have a large computer monitor!). There could even be settings to adjust how many results are displayed depending on screen size, what type of device one is using, personal preference, etc. There could also be settings to disable these advanced options for beginners or others who want to keep it simple.
I hope one or more of these suggestions intrigues you and others.
Also I am hoping for an iPhone app!
Keep up the great work!
Larry Maistros

4. Anonymous says:

James, please re-read my post.

The calculator says that the team with the ball would be better of with
a) first possession rules (opponent gets ball after own FG)
than with with
b) sudden death rules (own FG wins outright).
That makes no sense.

5. Anonymous says:

That is exactly what is happening Anon. The defense has more chance to score than the offense at the 2 yard line. if the defense scores in sudden death, it is game over. if the defense scores a safety in first possession, you still get a chance to come back, right?

If you were more likely to score than the defense, you would be correct in what you are saying.

6. Anonymous says:

No, defense scores on first possession = game over.
If you have the ball in OT, you are always better off with sudden death, because you always lose if the opponent scores next.

7. Felipe Azua says:

Do you have the WPA or EPA data available anywhere for download?

8. Thomas McDermott says:

Brian -

On Pro Football Reference's site, they've just put up their own WP Calculator, and they also gave out the formula they used to calc the numbers. Regardless of how good it is, etc., I admire the fact that they put it out there for us to check out.
Any chance you'll ever do something similar? I know this is a long shot because I believe the way you calc your numbers is much more complicated.
In any event, looking forward to seeing the upgrades to the WP Calculator. Thanks as always for a great site.

9. Anonymous says:

It still doesn't take into account time remaining and the possibilty of a Tie.

One would otherwise assume that the win probabilty in many/most down & distance combinations would tend towards 0.5 as time gets short in the (5th) OT quarter.

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