Penalties – an accurate distribution

It started with me thinking about the holding calls against the offense. How could I incorporate those instances where the holding occurred downfield and the 10 yd penalty applied from there, instead of from the line? But the more I looked into it, the more I realised that all of the penalties needed overhauling. So I looked at the 2013 season (it’s one where I have every playbook), and over a few months recorded every single penalty … 3419 all up.

Some findings:

on pass plays, the most frequent penalties were (cf. APBA’s) …
false start o 21% ( 3%) FAIL
pass interference d 12% (14%)
holding o 9% (14%)
holding d 9% ( 8%)
unnecessary roughness d 5% ( 3%)
neutral zone infraction d 5% (nil) FAIL

this compared with APBA’s (cf. ‘actuals’) …
holding o 14% ( 9%)
pass interference d 14% (12%)
holding d 8% ( 9%)
illegal contact d 8% ( 2%) FAIL
illegal formation o 6% ( 1%)
intention grounding o 6% ( 2%)
offside d 6% ( 1%)
pass interference o 6% ( 3%)
roughing passer d 6% ( 4%)

on running plays, the most frequent were (cf. APBA’s):
false start o 34% ( 3%) FAIL
holding o 20% (25%)
neutral zone infraction d 8% (nil) FAIL
delay o 8% ( 3%)
unnecessary roughness d 4% ( 6%)
encroachment d 4% ( 8%)

this compared with APBA’s (cf. ‘actuals’)
holding o 25% (20%)
offside d 14% ( 2%) FAIL
encroachment d 8% ( 4%)
holding d 6% ( 1%)
illegal block o 6% ( 1%)
illegal motion o 6% ( 0%) FAIL
facemask d 6% ( 2%)
unnecessary roughness d 6% ( 4%)
unsportsmanlike d 6% ( 0%) FAIL

so you can see that the distribution of penalties is way off. In particular, the failure to recognise that the most common penalty – False Start – is not represented appropriately bothered me. Of course a lot of it is a result of trying to squeeze in all the offense and defense fouls into 36 possible outcomes – it’s a hell of a lot better then the previous method which only had 11 outcomes – but it’s still nowhere near close enough (for me).

So how can it be done better? Simple – introduce 1 more die into the penalty roll. Same roll, just with 1 more die. That gives you 216 possible outcomes and you can model the distribution much more accurately.

Another thing I thought a lot about was the pass interference penalty. That 12% included all types of passes – long, medium and short passes – and we all know that there are a LOT more flags thrown on the long ones than the shorter ones. So I introduced different distributions depending on what type of pass you threw:
short & screen (S)
medium (M)
long (L)

so now we have the following distributions for defensive pass interference:
S 9%
M 17%
L 29%

Using these with conventional pass distribution usage will come pretty close to the actual figure.

I’ve looked at all of the penalties and redone them (mostly) with the extra die.

I changed some of the existing penalties to new ones as well:
1.Clipping – Offense is now 1.Facemask – Offense (clipping hardly ever was called, and there was no Facemask o)
5.Grasping Facemask – Defense is now 5.Neutral Zone Infraction – Defense (Facemasks are now 15 yarders when called, and there was no NZ Infraction d)
8.Illegal Block – Offense is now 8.Illegal Block Above the Waist – Offense (this one is 10 whereas all the other illegal blocks are 15 yarders)
15.Ineligible receiver downfield – Offense is now 15.Illegal Use of Hands – Defense (Ineligible Receiver d/f is now a 5 yarder and can be covered by Ineligible Player d/f, and there was no Illegal Use of Hands d)
30. Twisting Facemask – Defense is now just 30. Facemask – Defense (‘cos they don’t differentiate between grasping, twisting, turning, pushing or pulling; since 2008 it’s all just a 15 yard Facemask)

new penalties are:
36.Horse Collar Tackle – Defense
37.Illegal Touch of Forward Pass – Offense
38.Twelve Players on the Field – Offense
39.Illegal Chop Block – Offense
40.Invalid Fair Catch signal – Offense
41.Illegal Substitution – Defense
42.Delay of Game (after play) – Defense
43.Illegal Cut Block – Offense
44.Illegal Peelback Block – Defense
45.Delay of Game (after play) – Offense
46.Tripping – Defense
48.Taunting – Defense
49.Taunting – Offense
50.Offside – Offense
51.Delay of Game – Defense
52.Illegal Peelback Block – Offense
53.Illegal Touch of Kick – Offense
54.Player out of bounds on Kick – Offense
55.Illegal Formation – Defense
56.Illegal Blindside Block – Offense
57.Illegal Touch of Kick – Defense
58.Illegal Low Block – Offense
59.Illegal Low Block – Defense

All of these penalties will now be called more accurately according to their actual distribution.

Also I’ve done a ‘Special Penalty’ table for offensive holding, illegal-use-of-hands, and illegal block penalties, as well as live ball Personal Fouls, Unnecessary Roughness and Unsportsmanlike penalties by the offense. This table can be used when these penalties are called on running plays, passing plays for gain, and punt & KO returns, where the foul occurred either over the line or during the return. In these situations, the penalty is assessed from the point of the foul, not the line of scrimmage or point of possession. These are all based on the actual statistical spread of penalty enforcement locations.

And, I’ve introduced a No-Penalty result on kickoffs, because there just aren’t that many flags on the kickoff. Including kickoffs-out-of-bounds, I counted just 46 penalties all 2013 season on KO’s (I’m not talking about returns here, just the KO part). With 2684 kickoffs and (typically) 3 penalty numbers on KO cards, the cards would otherwise produce over 220 penalties for the season!

Similarly, on punt returns, the opposite occurs – there are actually a lot more penalties than the cards can produce. Typically there are 3 penalty numbers on PR cards, but there should be more like 7 to reproduce the actual number of penalties. I fix this by rolling an extra die on the punt return roll. If it is a 1, there is an automatic flag on the play. This would result in a 24% penalty percentage – that’s too high (it should be about 20%), so I introduce some No-Penalty TQ rolls to correct the percentage to reproduce the actual figure of just under 20%

I also separated KO return penalties (as TKO) from TK because they were completely different in their type & distribution. And with typically 3 penalty numbers on KO return cards, they also generated too many penalties.

Lastly, you may notice that I do pass interference penalties different to APBA and others. First, I think you should be able to decline the penalty and accept the completion. I don’t believe it skews the stats that much and it’s much more intuitive to me. Second, on incompletions I use the interception identifier columns to determine where the pass interference occurred. It seems more logical to me to do it this way.

Hope you find these useful. Feedback (and corrections) welcomed.


Version 2.0 Released

Added 10-June-2018: I have now released version 2.0 of the charts. I’ve revised them based on more research – specifically another full season, this time 2015.

This has resulted in me splitting TQ and TK into their own charts, and some changes to punt return procedure – now you ignore the penalty numbers coming from the returner’s card, and just rely on the third die you would roll to generate the penalty. Same with onside kickoffs – ignore the penalties off of the kicker’s card, and just rely on the third die you would roll to generate the penalty. There were just so many penalties on these plays that it was simpler just to do this.

Another change I made was to get rid of the Personal Foul penalty. In 2015, they only had Unnecessary Roughness and Unsportsmanlike fouls, with no Personal Fouls. So I followed suit. To be honest, I could never understand why we needed 3 types of personal fouls anyway.

The other significant change I made was to the Special Penalty Chart for fouls by the offense. I researched more thoroughly the types of fouls, when they occurred, and the typical distance applicable.

Feedback and corrections welcomed


Version 2.1 Released

Added 30-Oct-2018: fixed some errors in the charts and made some improvements.

New Penalty Charts v2.1

New Penalty Charts v2.0  now superseded by v2.1

New Penalty Charts v1.0 now superseded by v2.0

as always, feedback and corrections welcomed.


thanks, Phil

14 thoughts on “Penalties – an accurate distribution

  1. I finally had a chance to review your charts in detail. It’s quite obvious that you put a lot of thought and effort into them and I’m so grateful that you took the time to post.

  2. Phil,

    This is fantastic. You have done a wonderful job. This had to have taken forever-and-a-day to complete. I have already made arrangements to incorporate this into my game.

    One question (and this pertains to APBA’s rules too), what do you do on SCREEN PASSES BEHIND the line of scrimmage? Since Screen Passes are thrown BEHIND the line, and Pass Interference can’t be called behind the line, would you recommend making those Defensive Holding penalties. The NFL rules do allow for Defensive Holding in those situations, but not Pass Interference. Since you are the Penalty Expert, I would love to hear your opinion.

    Once again, what a fantastic job.


    • Thanks Doug.

      the way I do my pass interference calls (and this is in my notes under the TH penalty table), if the PI occurred on or behind the line, there is no penalty. So for -ve yardage completions, no penalty. If a pass was complete, and W74 or W75 revealed the PI occurred on or behind the line, then no penalty.

      It’s important to remember that with all APBA passes, just because a pass type was called does not mean that ended up being the play that happened. How else can you explain a screen pass being intercepted 31 yds downfield? There’s always the chance that the play unfolds in such a way that the QB goes off-script.

      cheers, Phil

      • Phil, excellent job with this. I use this site for penalty distribution:
        If you click on each team you can see the type of penalty called. Might help you validate 2013 and may help give you a more generalized distribution over a number of seasons.

  3. Phil,

    I just received my new 2017 cards so this is the first time that I have had to be able to actually test out the boards. They are even better than I thought. I now strictly use yours. They are much more realistic.

    Thanks again for such a fantastic innovation.


  4. Phil,

    I too am very impressed with your GREAT innovation and am setting up to use it very soon.

    I’m going through the TM & TL chart with am eye to programming the your charts to speed up my games. When I do I’ll make my program available to our community.

    A question early on? – On Kick-Offs the #35 Out-of bounds result? My prior research, using the 2015(?) season stats, indicated only 1 Out-of-bounds KO the entire season. Your chart shows 3 #35 results plus a partial #35 on #60. This seems way to many to me – the partial with #60 would be enough IMO.

    Am I missing something here?

    BTW – I’m pleased to see you include a Version # on your charts. Very thoughtful.

    • Thanks Ralph. I would hold off on using the version 1.0 charts, as I am about to release version 2.0 (about 1 week away). I took Mark Zarb’s advice and researched another season to verify the validity and accuracy of my results. Coincidentally, I used the 2015 season, so I have all the stats at hand, and can tell you that 17 of the 2550 kickoffs went out-of-bounds that season. For 2013 it was 26 of 2684. I’ve used these figures in my version 2.0 charts and now have 3 results at #35 and some partials to reproduce that statistically.

      • Phil – Thank You for your quick response and more accurate (than my) info, and very helpful analysis. You and Mark have really made greatly appreciated innovations that have enhanced our games. I’m looking forward to your V2.0 charts.

        It’ll take me a while to program my play-aid. Ive been programming since the early 60’s but I’m 86 now and not as sharp as I used to be :-).

        Oh, yes – I failed to mention; 1. I will not offer my play-aid on-line without you consent, and 2. You will of course be fully credited as the play-aids chart’s source and inspiration.

        Thanks Again and More later,
        a.k.a VaTech63

  5. Phil,
    I am about to do a replay of the 1984 season, what would you recommend as far as this innovation? Should I stick with the standard APBA charts considering the way they called penalties back then was completely different?

    • Keith, I would still use the charts, just enforce the penalties differently (as needed) according to the rules as they were back then. You should be able to Google the rule changes, and with a bit of research, go from there.

      Good Luck with your replay.

      Cheers, Phil

  6. Could I get an explanation of #44 on the TH penalties? The only thing I can think of is two penalties called on one play. Thanks!

  7. I’m assuming you mean the results at Line 44? No, there are not 2 penalties. the penalty depends on what pass was called. I should have notated it as 1S=2, 1ML=20, 2S=7, 2ML=20 etc. Sorry, I’ll fix it on my next version

Leave a Reply