49ers Red Zone numbers: How effective are they?
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As we've completed the final week of the season, we're down to our last "sponsored post" of the season. For this last post I was actually rather curious about everyone's thoughts on a specific issue related to the red zone and the 49ers. The most basic red zone statistic is "red zone efficiency." That statistic is determined simply by dividing touchdowns scored in the red zone by total trips into the red zone. On generally useful statistical site is teamrankings.com and they refer to it as "Red Zone Scoring Percentage," although it is the same mathematic equation.
Given that touchdowns are not the only way to score in the red zone, that last title (scoring percentage) is certainly a misnomer. In looking at all this, it's always bothered me that people would calculate the percentage this way. One alternative is of course Football Outsiders' use of DVOA, which they can apply down to specific zones on the field, including the red zone.
In looking back at 2009 through traditional stats and the more advanced metrics of FO, we see the following:
According to teamrankings.com, the 49ers finished 5th in red zone scoring percentage on offense and and 1st in opponent scoring percentage for red zone defense. According to Football Outsiders, the 49ers finished 4th on offense in the red zone and 2nd on defense in the red zone. So clearly the rankings are relatively close. Nonetheless, the idea of scoring percentage still drives me crazy. After all, according to the traditional "scoring percentage" formula, a touchdown is worth "1 point," if you will, while a field goal, interception, blocked field goal, turnover on downs, etc is worth 0 points in the formula. Wouldn't it make sense to give some kind of value to a field goal?
Looking back at the 49ers 2009 season, their offense finished 23/39 in the red zone based on the traditional formula. That means 16 of their red zone trips were "unsuccessful." In looking at those 16 specific visits to the red zone, the 49ers made 11 field goals, while having 2 turnovers on downs, 1 fumble, 1 blocked field goal and 1 missed field goal. The point of football is to score more points than your opponent. How can you say a field goal in the red zone is the equivalent of an interception?
If we look at the team's defense, the same issue arises. The 49ers defense finished 19/47 in the red zone, meaning 19 touchdowns were scored. Of the remaining 28 red zone defenses, the opposing offense successfully kicked 19 field goals, threw four interceptions, had 1 blocked field goal, 1 missed field goal, gave up 2 fumbles and had 1 turnover on downs.
Wouldn't it make more sense to potentially give 1/2 credit for a field goal in the red one? So, looking at the 49ers offense, instead of finishing with a red zone scoring percentage of 59% (23/39), they'd finish with a percentage of 73% ((23+ (11*.5))/39). Under that equation, you reflect the fact that the 49ers did in fact score some points. If you wanted, you could even knock it down to less than 1/2 credit since the odds of scoring a touchdown would likely be higher in the red zone. Either way, you'd be reflecting these other scoring situations.
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It always drove me nuts...
… that people call a team’s “touchdown percentage” their “scoring percentage.” Field goals, in the NFL, are extremely valuable, too.
yes, of course we all understand that field goals are an important part of scoring and should be reflected as such in some of these statistical equations. However I think the reasoning for discounting field goals as nothing when it comes to calculating these statistics is because of the general belief that once you’re in the red zone, it’s almost automatic that you should come away with at least three points. Scoring seven is something not every team can do, let alone do it consistently. That’s why I believe much more emphasis should be placed on defensive efficiency in the red zone, as opposed to the offensive side. 9 “empty” trips into the red zone for our D is tremendous. I’m curious as to where that stat puts us compared to other teams
Much easier, all-mighty Megatron, then attacking the real threat...The Autobots moonbase!!
by Brave Neander on Jan 6, 2010 10:33 AM PST up reply actions
I'm just saying...
… they should call it TD percentage, rather than scoring percentage.
word
Much easier, all-mighty Megatron, then attacking the real threat...The Autobots moonbase!!
by Brave Neander on Jan 6, 2010 11:03 AM PST up reply actions
the biggest problem
for the niners this year was that they didn’t get there all that often. Hard to score either td’s or fg’s when you go 3 & out.
Is there any evidence...
…that red zone efficiency — whether offensive or defensive — has any predictive value as a stat? In other words, are such performances reproducible from year to year? I’m skeptical because this debate (like finishing games) reminds me so much of baseball arguments about “clutchiness.” It seems to me this is a threshold inquiry that has to be answered “yes” or the whole question is moot.
wouldn’t the easiest way to do this be to just calculate the average number of points scored per red zone trip? if you just divided that by 7 you would get a percentage where a field goal is weighted as 3/7ths of a touchdown, which is accurate.
Interesting.....
What we've got here is a failure to communicate.
by chikmagnet_565 on Jan 6, 2010 1:44 PM PST up reply actions
what would actually be logical
is not to distinguish between the 20 yard line and the 21 yard line.
Roughly speaking, each point on the field has some average scoring expectation. For example, on your own 20 yl it’s 0. Receiving a kickoff I think is worth ~1 point. At your own 1-foot line, it’s about -2 (combine safeties + average FP for opponent). Note that this is why it’s often considered bad analytic football to kick field goals on 4th and goal. Not only is a FG only worth ~2 points on average (assuming opposing team has time for another drive), but pinning your opponent inside the 5 is worth (on average) 1-2 points in field position.
Kicking a FG inside the 5 is kind of like bunting in baseball. It’s not always the wrong move, but you should have a good reason.
Oh, I am digressing.
Anyway, if you wanted to get an “accurate” measure of redzone defense you could compare points scored against a defense from 1st down at the 1yd line, 2 yd line… 20 yrd line. Maybe smooth it over a 3-yard window vs. the league average.
Probably FO has this buried (or at least, derivable from) in their premium stats that I don’t pay for!
Just using “possessions inside the 20” doesn’t account for the fact that a 1st and goal from the 5 is somewhat difference from a first and 10 at the 20 in terms of expected points.
And of course, you would have to adjust for strength of opposition.
FIRE BRIAN SABEAN... UNLESS HE KEEPS DRAFTING WELL. .. AND SIGNS UNDERRATED PLAYERS LIKE AFFELDT OR PHELPS. .. OR ALRIGHT WHO'S PLAYING WITH THE ALIEN MIND-SWITCHING RAY?
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PARPG- Indy post-apocalyptic roleplaying game currently in early planning stages.
hey fooch...
simple solution…use “points per trip to the red zone”…FGs become worth half of TDs, and a turnover — whether on downs, via an INT/fumble, or via a missed FG — is worth 0.
so, niners OFF had 171 pts in 39 trips to the red zone, or 4.38 pts per red zone trip.
niners DEF allowed 171 pts (exactly the same? a coincidence?) in 47 opponent trips to the red zone, or 3.68 pts per opponent red zone trip.
wonder how that stacks up against the rest of the NFL.
I would go with that plus...
Adjust for turnovers committed or forced in some way. Since every turnover is a potential scoring chance, do it this way: points scored – 5 X turnovers (just say for the sake of argument it’s 50/50 you could have scored a TD or FG on the drive that ended on a turnover) / divided by visits to the red zone.
I would also like to see a stat like this but calculated from the 30 and not the 20, since if you reach the 30 you are in effective field goal range, so close enough that you should score.
Hard to argue
That Singletary isn’t the real deal
their schedule once you take away the 2 games each with the Rams and Seahawks,,played some potent offenses practically every week..
it’s all P.Willis and Mike…one comes to play and the other prepares everyone else for war
(Skins fan)

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