AztecSportsReport.com - Complex chart will determine fourth down decisions

August 30, 2012

Agustin Gonzalez
AztecSportsReport.com Publisher

Has San Diego State head coach Rocky Long truly turned into a mad genius?

Heading into fall camp, Long's idea started simply enough: The offense would go for every single fourth down when it was past the 50-yard line and on the defense's side of the field. But as the first game of the season inched closer and closer, that simple idea has turned into a complex algorithm and a very important chart that will dictate what the Aztecs do on fourth down this season.

When a professor from SDSU's business school heard about Long's potential fourth down philosophy, he e-mailed the head coach, eager to help out.

The professor used NFL statistics to create an algorithm that calculates how many points a team can expect to score (1) if they punt, (2) if they attempt a field goal, and (3) if they go for it on fourth down -- from every single yard line on the field, goal line to goal line. He pitched this algorithm and his findings during an hour and a half seminar with the coaching staff last Friday.

The coaches liked what the professor had to say, and bought in. They gave him all of the team's statistics over the past four years, and he in turn plugged them into his algorithm to produce a chart that SDSU will use against Washington on Saturday to determine what the team will do on fourth down.

"I wish I could explain it right because it's very, very detailed," Long said.

This is how the SDSU head coach described the very complex algorithm and chart:

-- With the help of graduate assistant Zach Arnett, the business school professor analyzed everything the Aztecs have done over the last four years and put it into an algorithm with all SDSU stats on turnovers, third down conversions, fourth down conversions, net punting and field goal percentage from all different areas on the field.

-- In the algorithm, you input the down and distance and field position, and using the team's statistics it comes up with the points you can expect if you try a field goal, if you punt, or if you go for it on fourth down. If the points you get when you go for it outweigh the others, you should go for it.

-- The algorithm takes into account both SDSU's offense and the specific opponent's (in this case, Washington's) defense on fourth down from everywhere on the field.

-- To decide if you should kick a field goal or go for it, the algorithm looks at how likely the opponent will score from the average field position of where they get the ball when SDSU kicks off after a successful field goal. (Hypothetical example: Is it more advantageous to go for it on 4th-and-3 from the 20-yard line and risk turning it over, or kick a field goal and have Seamus McMorrow kick off, where on average the opponent will return it to their 30-yard line?)

-- Injuries will be taken into consideration, making this truly a week-to-week philosophy. (Hypothetical example: The team's starting quarterback gets injured and has to sit out the next game, making the team less likely to be successful converting fourth downs.)

-- The strength of the opponent will also play a factor. The better the opponent, the more advantageous it would be to punt and control field position or kick a field goal for easy points. The better you are than the opponent, the more advantageous it would be to go for it and put up seven points instead of three.

-- A significant problem with the algorithm and chart is low sample size. If a team attempts 1,000 fourth downs in a season, the math works out perfectly. But SDSU won't get nearly that many fourth down attempts this season, so there is a larger margin of error with the odds. To help offset this, Long and his staff will use stats from every NCAA Div. I football team in the country this season to get a bigger sample.

-- In summary, the chart basically tells you (mathematically) what the best thing to do is from anywhere on the field on fourth down, organized by 4th-and-1, 4th-and-2, 4th-and-3, and so on.

"You would be shocked by what the chart tells you," Long said.

Only time will tell if the Aztecs go for every fourth down on Saturday, or decide to punt and kick field goals, but Long will have his handy dandy chart to reference and make each individual fourth down decision based on statistics, not emotion or gut feeling.

"The decisions on Saturday will be purely what gives us the best chance to win. But statistically, it will give us the best chance to win. Statistically."

7-Day Free Trial: Get premium access to AztecSportsReport.com!

FEATURED PRODUCT