Article CategoriesAFM Magazine
|
Variables 101 – Knowing how to analyze over 100 offensive variables gives your defense a statistical edge.by: Brian FleuryDefensive Backs Coach and Special Teams Coordinator, Towson University © More from this issue Knowing how to analyze over 100 offensive variables gives your defense a statistical edge. Every defensive coordinator has his own style and process in preparing a game plan for the next opponent. Part of this process is detailing the statistical side of probability on the opponent’s play selection. Ideally, each defensive call has the probability of being successful, helps create one-on-one favorable match-ups and allows the players to execute the proper techniques in stopping the offense. If two out of these three criteria are met on each play, it will usually be a successful play for the defense. GAME PLAN PROCESS When performing any sort of data analysis it is also important to understand the variables and how they interact with each other. Different combinations of variables in different order will give a varying array of percentages. For the purposes of defensive game planning, there are five variables that are considered “Primary Variables”. They are: Beyond the primary variables, there are secondary variables that should also be analyzed. These variables provide information that is not guaranteed to be obtained prior to the snap and, therefore, is typically not used to determine the initial defensive play selection. These variables include: Finally, there are ‘Tertiary Variables’ that can be used similar to secondary variables. But they are not typically used in traditional data analysis. Tertiary variables are identified through intensive film study and are not always present. Some examples of these variables include: 4. Score of game = lead/deficit is less than 21 points For example, a 2nd and short situation may be viewed as a choice down (2nd and short run/pass percentage consistent with overall R/P percentage) for some offensive play callers, and it may be seen as an opportunity to take a shot at a big play for some others, as indicated by a significantly higher pass percentage. If 2nd and short is determined to be a choice down, then personnel remains the primary variable used to establish the tendencies. If 2nd and short is determined to have a significantly higher pass percentage, then the D and D overrides personnel as a means to ascertain the R/P and play selection tendencies for that particular offensive play caller. This example highlights the need to analyze the data in multiple forms in order to determine which percentages are most relevant to a particular offensive play caller, and, hopefully obtain an indication as to his play calling philosophy in any given situation. This process requires that we examine the following data reports containing primary variables on a weekly basis (in order to consolidate the data, D and D and Field Zone are grouped into relevant sub-categories; i.e., short, medium, long, red zone, grey zone, etc.): 15. R/P by personnel by two-minute 37. R/P by D and D by field zone by two-minute In situations where the opponent tends to run the ball 40% or more of the time, we will choose defenses best suited to stop the run while maintaining the integrity of our pass defense. The base defenses will utilize stunts designed to attack the blocking schemes of the opponent’s favorite run plays combined with coverages that tend to give us a numerical advantage and allow us to cancel every offensive gap. The pressures will be selected based on their ability to attack the offense where they are likely to be running the football while maintaining integrity against less likely plays. In situations where the opponent tends to pass the ball 61% or more of the time, we will choose defenses best suited to stop the pass. The base defenses will utilize coverages designed to give us the best chance for success against their favorite route combinations while using stunts that allow us to stress the protection scheme being utilized by the offense. The pressures will be selected based on their ability to attack the protections and threaten the quarterback while utilizing coverages that give us the best chance for success against their favorite route combination. As a general rule, the game plan is formulated with the intent on stopping the run first. This is why we continue to focus on stopping the run in situations where the offensive tendency is to throw 60% of the time. In these situations, both base and pressure defenses will be selected based on their ability to stop the probable runs. Notice that on passing downs, the priority in base defense is to cover the routes and the priority in pressure defense is to threaten the quarterback. Selection of base defense vs. pressure on passing downs is typically based on the ability of the opposing QB in three categories. Does he have a strong arm? Is he intelligent or does he make good decisions in the pass game? Is he accurate with his passing? Keep in mind that we might evaluate an opposing quarterback to be strong in any combination of the three categories, or deficient in any of the three categories. In situations where a deficiency is not present, we will plan to attack the opposing quarterback with whatever we feel we execute the best. The philosophy surrounding this thought process is best illustrated by the diagram above. For example, if a QB is deemed to be accurate and intelligent, but does not have a strong arm, we would plan to utilize more 8-man drop coverage in an effort to limit the amount of space there is for the quarterback to fit the throw. The combination of smaller throwing lanes and increased flight of the ball due to the lack of arm strength should allow for more disrupted passes. The variable that changes this philosophy is always the ability of the quarterback to extend the play by running the football. This will typically limit the amount of man coverage played by the defense and significantly decrease the number of available huddle calls. We will also examine the following data reports containing both primary and secondary variables: This data will be analyzed along with intensive film study to determine if the defensive play caller would like to utilize any “Checks and Audibles” for the particular game. Typically, a R/P or play selection tendency has to be greater than 85% in order to justify the investment in a “Check” or “Audible” for that situation. In many cases, it is better to advise the players of any relevant tendencies and allow them to anticipate the selected offensive play giving them a physical advantage, rather than investing in a “Check” or “Audible”. The same holds true of any tendency derived from evaluation of the tertiary variables. Finally, there are certain “Special Situations” which may lend themselves to create specific tendencies on the part of the offensive play caller. These situations are based on a variety of variables typically extending beyond the three-variable maximum utilized in general game planning. They do, however, tend to establish tendencies worthy of consideration in the defensive game plan. There are also potential personnel tendencies which are analyzed and may provide insight as to the offensive play caller’s general game philosophy. If broken down properly, these tendencies can typically be viewed in the following reports: Once the data analysis is complete, we should have a list of base and pressure huddle calls prepared for the most prominent situations and tendencies provided by the data. The amount of huddle calls for each situation should be relative to the ratio of occurrence per game for that situation. For example, there will be significantly more huddle calls available for normal situations than there will be for 2nd and long with the ball on the -2 yard line. It is also important to understand that the goal of a defensive game plan is to force the offensive play caller out of his comfort zone and, therefore, force the offense to do something it is not accustomed to in order to win the game. With this in mind, the defensive game plan should provide the best opportunity to stop the offense’s 3-5 favorite runs or passes in any given situation. If the opponent broke a 50-yard run, but only ran this particular play once in five games, the defensive play caller should not be including a defense in the game plan that stops that play, but may be weak against the play they run 10 times a game in a similar situation. This requires great discipline on the part of the defensive coordinator, but is necessary in order to guarantee the efficient use of time in the staff room and at practice. DETERMINING THE FAVORABLE MATCHUPS Once this is completed, it is important to review the possible defensive huddle calls against the 3-5 favorite runs and passes in any given situation and discuss the potential one-on-one matchups that will result from the clash of the two opposing schemes. Generally speaking, any defensive call that may potentially result in significant amount of favorable matchups for the defense should be highlighted. Conversely, any defensive call that may result in a significant amount of unfavorable matchups should potentially be removed from the game plan. It is important to recognize that this process is largely subjective and requires careful consideration on the part of the defensive staff. Suppose a defensive call presents extremely favorable matchups against all of the offense’s plays except the one they run the most. The decision to carry, and ultimately call the play in a game situation is that of the defensive play caller and is based on his capability to evaluate his own defensive players compared to the opponent’s offensive players. The ability to influence the outcome of the game may often be found in a play caller’s efficiency in predicting favorable matchups for the defensive personnel and repeatedly putting them in a position to succeed. For example, if playing cover 2 gives the defense a schematic advantage in a given situation, but historically, the defense is giving up 10+ yards per pass attempt in cover 2, the defensive play caller may want to remove the call from the game plan. In addition, if the defensive coordinator knows that the players execute a certain pressure with great confidence, he may want to highlight the opportunities to call that pressure within the game plan. This philosophy extends beyond the team concept as well. A good coordinator will be aware of individual strengths and how they relate to defensive huddle calls. For example, if a player is not an effective pass rusher, it will probably be more efficient to utilize him in coverage, even if he has a favorable one-on-one matchup in pass rush situations. Awareness of the strengths of the players adds another variable to the play selection process. However, these variables deserve consideration and can often be used to help the defense gain confidence over the course of a series or a game by putting the players in a position to utilize their strengths and experience success. In other words, if you plan to pressure 65% of the time in games, you should pressure 65% of the time in practice. The same is true of other situations as well. If 30 out of 75 snaps in a game are 1st and 10 (30/75 = 40%), then 40% of the reps in practice should be focused on defensive calls vs. offensive calls that will likely occur on 1st and 10. Over the course of the week, the coaching staff must evaluate the effectiveness of the defenses being utilized and potentially eliminate those that have proven unsuccessful in practice. If done efficiently, the game plan will be reduced and become more concise. The final product will be a list of calls for given situations that have a probability of providing a schematic advantage, while presenting favorable one-on-one matchups, and cultivating confidence over the course of the game. However, the defensive play caller must be cautious about paralysis by over analysis. It is impossible to call the perfect play for every situation. We take a mathematical approach to planning and come up with the best plan based on probability, but it is important to remember that there is always a human element that can, and will, deviate from the percentages and defeat the science. The goal is to study, absorb, and commit to memory as much information as possible over the course of the week. Know the plan, trust your own preparation, and at the end of the day go with your gut. |
|
HOME |
MAGAZINE |
SUBSCRIBE | ONLINE COLUMNISTS | COACHING VIDEOS |
Copyright 2024, AmericanFootballMonthly.com
All Rights Reserved