Why do they give up so many safeties?
This is the piece I’ve been waiting more than two years to write. Me asking myself “Should they really be giving up all these safeties?” has led me through hundreds of hours of research, many more of talking to people and even a couple of banging my head against the desk.
Having been the play-by-play voice of the Manitoba Bisons for the last eight seasons, I’m intimately familiar with the safety. Any time the Bisons start a drive pinned in their own end, you know if they don’t gain many yards on first and second down, the safety is coming. Head coach Brian Dobie gives up the 2. Every time. (Okay, not every time … 32 out of 34 times that they were on or inside their own 14. And one of two those punts was in the late stages of a blowout loss.)
Brian’s been a coach forever. And though on a couple of occasions I’ve posed an alternate theory toward safeties, he’s good. He knows what he’s doing. As the wise philosopher Anonymous once said: “A man with an experience is never at the mercy of a man with an opinion.”
When I discuss football strategy with people, I think some of them miss an essential part of conceding a safety. They figure “Giving up two points is better than a field goal or a touchdown.” The thing is that a safety isn’t just giving two points. It’s giving two points and the ball to your opponent.
As we saw in past articles, possession can be very valuable. For example, intercepting a pass at our opponents’ 40-yard line is expected to yield 3.43 points on average. Knowing the value of possession allows us to analyze situations — such as conceding a safety vs. punting — and see what course of action the numbers suggest.
Looking at all the safeties conceded in Canada West from 2005-12, the average field position a team gets after receiving a free kick is their 42-yard line. On average, their post-free kick field position is worth 1.42 points to them. Add in the 2 points for the safety and our decision to concede really costs us 3.42 points.
So we see it’s clearly worse than just the two points on the scoreboard. But is it worse or better than punting from deep in our own end?
To figure the value of punting, I’ve considered a couple of factors.
- The value of the field position they would get after we punt.
- The value of the field position we would lose on our next drive.
- The percentage of times we get a next drive without a score on their drive.
The second point may require some explanation. Say we chose to punt to them and they return it to our 50. We know we could have made them take possession on their 42 (on average, by conceding a safety). There’s an 18-yard difference that punishes us on our next drive. I think that needs to be accounted for in making a complete decision.
Now we aren’t punished every time. Any score would reset field position. So:
EV field position * % drives with no score = weighted EV of field position
(This has flaws too because decision-making of the offensive team can change greatly at different points on the field. But it’s the best I have so far.)
Teams fear that if they don’t give up a safety and choose to punt, they’ll immediately put their opponents in field-goal range. And since 3 > 2, teams choose to give up the safety. But you might be surprised at how often teams score when starting in our territory.
Even if they start between our 31- and 35-yard lines they fail to score any points on more than 30 per cent of the drives. And less than 40 per cent of the time will we give up a touchdown.
The average punt in Canada West is a net of 30 yards. So if we punt from our 1-5, we expect them to take over at our 31-35. Having recently expanded the data to include every meaningful drive from 2004-12, they should expect to score 3.5 points starting in that range.
Now we compare that field position to starting at their 42. That costs us 34 to 38 yards of field position on our next drive. The average value of that much field is 1.62 points.
Now we are not punished like that every drive. We lose that only if they don’t score on their drive. As we saw in the chart, that is 30.4 per cent of the time. That means the field position we’re conceding is worth 0.90 points.
So let’s put it all together:
|EV of our 31-35||3.50|
|Weighted EV on our next drive||0.90|
On average, punting from our 1-5 yard line costs us 4.40 points. Giving up the safety costs us 3.42 points. That makes conceding safety a better decision for us by 0.98 points — a large margin.
I’ve done the same calculation for other ranges inside our 20:
You can see punting from our 6-10 yard line is less of a mistake, but still a mistake. But then it turns around dramatically.
Punting from our 11-15 is actually 0.76 points better than conceding a safety. When compared to drives starting from our 36-40, the percentage of time they score a TD or FG drops dramatically when they start a drive from our 41-45.
(Side note: a similar drop occurs in the CFL.)
Looking at all the safeties that Coach Dobie of the Bisons has conceded in my time, ignoring those caused by bad snaps or blocked punts, there are 14 of 38 that the data suggest should have been punted. Of course, the data can’t attest to the factors we need coaches for — weather conditions, quality of punter/punt team, time/score of game, etc.
Were they all under average conditions, those 14 would have been worth another 10.7 points to the Bisons according to my calculations.
TOUCHDOWNS AGAINST COST US BIG
When discussing this with Bisons defensive co-ordinator Stan Pierre, he brought up an interesting point. He said he was concerned “with the quality of the negative.” Essentially, Stan was saying that a TD — while worth seven points on the scoreboard — really hurts your team more than just the seven points.
I thought that was interesting. So I calculated touchdowns at a value of both eight and nine points just to see the results.
Even when giving two extra points for a touchdown (which is substantial for a single drive), nothing changes. Us punting from the 10 and in remains a mistake, and becomes more of a mistake. Us punting from the 11 and out remains a good decision — by a large margin.
In the end, calculating if we should punt is all about where our opponents will take possession. And the numbers show them starting a drive on our side of midfield is not always dangerous. I used a six-year average of punters in Canada West here. If we were to expect our punter/punt team to net 35 yards, then punting from the 6-10 becomes correct. As long as we expect our opponents to start from outside our 40-yard line, punting becomes correct under average conditions.
Week 3: Conceding a single point
Next: Do we see the same things in the CFL?
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