New Feature: Time Calculator

Someone tell Norv Turner there are no timeouts in press conferences.

I created a new tool to estimate the time at which a trailing defense (or soon-to-be-trailing defense) can get the ball back if they force a stop. The results are based on the time at the first down snap of a series and the number of timeouts remaining for the defense. You can adjust the expected duration of each play and the time consumed between the previous whistle and the next snap when the game clock is not stopped. The defaults are 6 and 39 seconds respectively. The calculator assumes there will be no stoppages due to reasons other than timeouts and the two-minute warning, such as incomplete passes, runs out of bounds, or penalties.

One additional feature is that you can check a box called "Save Timeout." This will indicate that the team on defense would prefer to allow the clock to wind down to the two minute warning rather than stop the clock with a timeout. For example, if the defense has one timeout left and the second down play ended at 2:10, the defense can elect to save the timeout for its offense in exchange for running down the 10 seconds to 2:00. This is, in effect, a trade-off between the 10 seconds of game clock and having a timeout available for an offensive drive.

It's very difficult to quantify the value of the timeout on offense. It's intuitively very valuable because an offense can use the middle of the field, which otherwise allows the defense to guard the sidelines.

Try this: Enter 2:24 remaining with 3 timeouts. Leave the 6 sec and 39 sec defaults for play and inter-play durations. Click calculate with the Save Timeout option unchecked and checked (with the 12-second default cutoff value). With 'Save Timeout' checked, you get the ball back with 1:54 and retain a  timeout for your offense. Without the option checked, you get the ball back with 2:00 on the clock and no timeouts, with the 2-minute warning essentially going to waste.

This option usually only makes a difference when the defense begins the series with all three timeouts remaining. It also may be smart depending on when a team can expect the change of possession to occur. The defense does not want change of possession to occur on a play that spans the two minute warning because that combines two potential clock stoppages into a single stoppage.

The workings of the NFL game clock is far more complex than it might seem. That's why I forced myself to build the calculator and think through all the considerations. The algorithm behind the calculator is basically a by-product of the one I used to create the chart below, which underpinned my analysis of when a defense should prefer to intentionally allow a TD.



There are two differences between the chart and the calculator. First, there is the 'Save Timeout' option in the calculator. And second, the calculator results walk through each play of the series and spells out the details of clock times, the timeouts, and the two minute warning for each situation.

You can game the calculator a little to account for some contingencies. If the ball goes out of bounds, the offense throws an incomplete pass or there is a penalty, there would be an additional stoppage, sparing a timeout for the defense. To estimate this possibility, just add a notional timeout to the actual number remaining. And if the defense already started with a full three timeouts, you can add one to the resulting number remaining at the end of the series.

As with everything around here, this is in indefinite beta status. Let me know if anything is buggy.

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6 Responses to “New Feature: Time Calculator”

  1. Keith Goldner says:

    This is great, Brian. What if you added a feature to the 4th down/WP calculators to adjust for this time calculator (since right now they aren't completely factored in)? Could you do some sort of timeout-adjusted time left to adjust the WP?

  2. Anonymous says:

    People will ask you for analysis on the New England decision to go for it on 4th and 2 from their own 10. My question is: when they miss, shouldn't they have let SF score a TD on their first play? Seems like the odds of scoring 2 TDs are better than forcing a turnover or forcing a missed FG.

  3. Nate says:

    Going for the stop seems like the smart move: If aware, the 'niners could go for second and short, which is basically game over.

    Assuming the stop is certain, the Pats have choose between 1:56 to score 10 points, or 2:15 to score 14.

    Brian claims that timeouts are not that important to the offense, and that field goals are more than 20 seconds faster, and more likely than touchdowns:
    http://www.advancednflstats.com/2012/12/when-to-intentionally-allow-touchdown_11.html

    Based on those assumptions, the stop is a better choice.

  4. Paul Thomas says:

    There is another little timing quirk that I see teams screw up constantly, relating to the two minute warning. It came to mind because the situation Brian discusses (2:24 to go and 3 defensive timeouts) is one I've seen enough times for it to trip alarm bells in my head.

    Here's the quirk: It is a very bad idea in the NFL for the defense to engineer a situation in which the offense has the ball on third down with between 2:15 and 2:01 to go, because that opens up the possibility of a "freebie" pass play.

    Imagine the 2:24, 3 defensive TO scenario that Brian discussed. Play #1 is a run that takes 7 seconds and gains 2 yards. The defense calls a timeout. Play #2 is a run which takes 6 seconds and gains 1 yard.

    If the defense calls a timeout here, the end result is 3rd and 7 with 2:11 to go. If the offense throws an incomplete pass (4 seconds) and then punts (10 seconds), the two-minute warning is wasted and the defender gets the ball back with ~1:57 to go and one timeout. If the pass is completed for a first down, of course, the game is essentially over.

    It is far better to let the clock run down to 2 minutes on second down. That forces the offense to choose between a pass play (which could give the ball back to the defender with 1:46-ish to go and two timeouts instead of one) or a run (which will almost certainly give the ball back to the defender with 1:46-ish to go and one timeout).

    If the opposing team is run by a conventional coach, this play will take you from a ~60% chance of getting the ball back with 1:57 and one timeout to a ~90% chance of getting the ball back with 1:46 and one timeout (clearly superior; 11 seconds doesn't make that much difference compared to the likelihood of actually getting possession again). And if the opposing team is run by a risk-taker, this play will take you from a ~60% chance of getting the ball back with 1:57 and one timeout to a ~60% chance of getting the ball back with 1:46 and two timeouts (again clearly superior).

    In other words, no matter what choice the opposing team makes, the defender is better off not spending a timeout on second down. Counterintuitively, you want to call your timeouts on first down and then on third down only "if necessary".

    For the same reason, don't call a timeout on FIRST down if it will leave 2:07 to 2:01 left, because if you do, the offense will get to freeroll second down in what amounts to "normal offense" mode (pass and run equal a priori) instead of "four minute offense" mode (run strongly preferred a priori).

  5. Brian Burke says:

    Paul-Excellent comment!

  6. Luke says:

    Paul-Couldn't agree more. Feel like I've been saying this for years, but just without a proper forum to discuss it.

    Add to this theory that we are assuming perfect clock and football execution by both teams. The Bears/Broncos game of 2011 comes to mind when the Bears ended up running out of bounds late in the game rather than staying in and keeping the clock running.

    By not taking the extra timeouts, the defense forces the offensive team to execute perfectly. Any offensive mistake greatly increases the defenses odds of getting the ball back AND getting the most time.

    From an outsider's perspective, timeouts act as crutches to the team's failure to execute (getting the play in on time, getting the right personnel on the field, mischallenging a ruling) or their lack of (score and) remaining clock. Spending a timeout that fails to maximize the amount of time left for your offense is in itself a failure to execute, which only devalues the timeout.

    Which leads to question, what is the EPA/WPA of a timeout as the clock winds down?

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