Impact of Field Position on Hawk's 2009 Defense
Posted 08-30-2010 at 10:33 AM by hawkeyeglory
If you made it this far you either 1) did not read my first blog entry "Impact of Field Position on Hawk's 2009 Offense" or 2) you’re a closet stat guy (or gal). If you fall into the first category, you might want to check out my first blog entry and if you don't make it back here you can consider yourself normal. If you fall into the second category, the first step in resolving a problem is admitting you have one.
Now onto the Hawkeye defense. After listening to the Iowa practice special on the Big Ten Network, it was great to hear this defensive stat… #1 in CFB for TD's allowed from scrimmage over the last two years. The question we are asking here is how much does field position play a part in that success? The short answer is not as much as you think. In fact, field position played a much bigger part in the 2009 Hawkeye offense scoring points then the stout 2009 Hawkeye defense preventing points which is a testament to how good this defense really was.
On possession started within the opponent's 1-39 yard line the Hawks allowed their opponents to score (TD or FG) on a measly 15% of possessions. When the opponent received possession within the 40's, they scored on a surprisingly low 33% of possessions. I thought these results might be a case of competition skewing the stats but when I looked at conference games only, the percentages were almost identical. Below is a chart detailing the results:
Starting yard line/Scoring rate against as a % of total possession started
Own 1-19 yard line - score 16% of the time
Own 20-39 yard line - score 15% of the time
40-40 yard line - score 33% of the time
Opp 39-20 yard line - score 50% of the time
To get some perspective, the 2009 Hawkeye offense (which did not set the world on fire) scored 27 % of the time or at an 80% greater clip then Hawkeye opponents when possession was started from their own 20-39 yard line and scored 55% of the time or at a 67% higher clip when a possession was started between the 40's.
It is also interesting to look at average starting field position when taking a gander at some of these numbers. As you can see, starting field position is a big part of the Hawkeyes success. Below is a chart showing starting field position as a percentage of total possessions for the Hawks and their opponents:
% of Possessions Started
Hawks
Own 1-19 - 16%
Own 20-39 - 58%
40-40 - 19%
Opps 39-20 - 5%
Opps 19-1 - 2%
Opponents
Own 1-19 - 24%
Own 20-39 - 58%
40-40 - 12%
Opps 39-20 - 5%
Opps 19-1 - 1%
You will note that the "Donahue effect" is in full force here as the Hawk's opponents started 24% of their drives from their own 1-19 yard line…8% more then the Hawks. Furthermore, you can see that the Hawks started 7% more of their drives between the 40's. As we saw when looking at the offensive stats, the Hawk's scoring chances increase considerably when they start a possession within the 40's.
Overall, I hope this give you some perspective on the importance of field positions for this Hawkeye team. Next time you are watching a game and Donahue drops a ball beautifully on the 5 yard line, you'll have some perspective on what it means. You will know how important it is for the Hawk's defense to try to keep the opponent from crossing their 20 yard line so the Hawk's offense will have a chance to take possession between the 40's as their scoring chances will go up dramatically. You now also know that the Hawkeye defense still has a better then average chance of shutting down opposing offenses even when their starting filed position is around mid-field. I will continue to look behind the numbers and post anything of interest to this blog. Until then, Go Hawks!
Now onto the Hawkeye defense. After listening to the Iowa practice special on the Big Ten Network, it was great to hear this defensive stat… #1 in CFB for TD's allowed from scrimmage over the last two years. The question we are asking here is how much does field position play a part in that success? The short answer is not as much as you think. In fact, field position played a much bigger part in the 2009 Hawkeye offense scoring points then the stout 2009 Hawkeye defense preventing points which is a testament to how good this defense really was.
On possession started within the opponent's 1-39 yard line the Hawks allowed their opponents to score (TD or FG) on a measly 15% of possessions. When the opponent received possession within the 40's, they scored on a surprisingly low 33% of possessions. I thought these results might be a case of competition skewing the stats but when I looked at conference games only, the percentages were almost identical. Below is a chart detailing the results:
Starting yard line/Scoring rate against as a % of total possession started
Own 1-19 yard line - score 16% of the time
Own 20-39 yard line - score 15% of the time
40-40 yard line - score 33% of the time
Opp 39-20 yard line - score 50% of the time
To get some perspective, the 2009 Hawkeye offense (which did not set the world on fire) scored 27 % of the time or at an 80% greater clip then Hawkeye opponents when possession was started from their own 20-39 yard line and scored 55% of the time or at a 67% higher clip when a possession was started between the 40's.
It is also interesting to look at average starting field position when taking a gander at some of these numbers. As you can see, starting field position is a big part of the Hawkeyes success. Below is a chart showing starting field position as a percentage of total possessions for the Hawks and their opponents:
% of Possessions Started
Hawks
Own 1-19 - 16%
Own 20-39 - 58%
40-40 - 19%
Opps 39-20 - 5%
Opps 19-1 - 2%
Opponents
Own 1-19 - 24%
Own 20-39 - 58%
40-40 - 12%
Opps 39-20 - 5%
Opps 19-1 - 1%
You will note that the "Donahue effect" is in full force here as the Hawk's opponents started 24% of their drives from their own 1-19 yard line…8% more then the Hawks. Furthermore, you can see that the Hawks started 7% more of their drives between the 40's. As we saw when looking at the offensive stats, the Hawk's scoring chances increase considerably when they start a possession within the 40's.
Overall, I hope this give you some perspective on the importance of field positions for this Hawkeye team. Next time you are watching a game and Donahue drops a ball beautifully on the 5 yard line, you'll have some perspective on what it means. You will know how important it is for the Hawk's defense to try to keep the opponent from crossing their 20 yard line so the Hawk's offense will have a chance to take possession between the 40's as their scoring chances will go up dramatically. You now also know that the Hawkeye defense still has a better then average chance of shutting down opposing offenses even when their starting filed position is around mid-field. I will continue to look behind the numbers and post anything of interest to this blog. Until then, Go Hawks!
Total Comments 0
Rss