Offensive Efficiency: TD% and Points Per Drive
This is the fourth part in my series about offensive efficiency. In case you missed the other three:
Today we look at perhaps the most obvious of all the variables in the discussion of “What Makes An Offense Efficient?”: Touchdown % and Points Per Drive. The goal of an offense should be to score a touchdown on each and every drive. While there are some productive non-scoring drives (the field position scenario I touched on earlier), a touchdown should be the ultimate goal of an offense on every drive except for those where a team needs a FG to win a game in the final minutes. So the best offenses should be thought of as those which score touchdowns the most frequently. Here are the best and worst teams in terms of the percentage of drives which culminated in a touchdown (TD%):
1. In most cases (with the exception of FG attempts at the end of a half/game or in overtime) a field goal attempt is the result of offensive failure. While it’s a better result than a punt or turnover, it still indicates a stalled (i.e. inefficient and/or unsuccessful) drive.
2. Field goals aren’t a sure thing. A team’s ability to convert FG attempts is dependent upon its kicker. Therefore, a team’s points scored off of field goals cannot be wholly attributed to its offense. Furthermore, a missed or blocked FG can set up an opposing team with great field position – giving them a better chance at scoring. Any time your offense is putting your defense at a disadvantage, you are giving your opponent a scoring advantage.
3. Settling for field goals allows your opponent to outscore you. Any time you score a field goal, you are allowing the opponent a +4 (or 5, if they go for 2) point swing if they convert their ensuing drive into a TD.
That said, the job of an offense is to score as many total points as possible. After all, a failed drive which leads to a field goal is better than failed drive which ends in a punt or turnover. A good stat to measure an offense’s scoring efficiency is their Offensive Points Per Drive (OPPD). Here again are the best and worst Point Per Drive offenses since the 1970 AFL/NFL merger:
Now looking at those 4 charts you might notice that for roughly every 1% increase in TD% we expect to see an increase of 1 PPG. Since 1970 there have been 1189 team seasons. In that span, teams have averaged 19.1 PPG and have scored TD’s on 19.5% of their drives. 995 of the 1189 teams fall between .85 and 1.15 PPG per TD%. Here it is in graphical form:
In 2010, the average PPG (combined offense, defense, special teams) was 22. So, an offense which scored TD’s on roughly 23% of their drives should be (on average) a winning team. Here are those teams:
You’ll notice 3 non-winning record teams here: Jacksonville, Dallas and Houston. All 3 teams allowed 400+ points (25 PPG). Noticeably absent from this list were the Jets (11-5), Steelers (12-4) and Ravens (12-4) who were the 6th, 1st and 3rd best defenses (points allowed) respectively.
The next part of this series will focus on points in a different way, measuring the points per yard ratio of a team.