1. Y’all Need a Runninback?
By: Chris Torgalski & Jin Lee
Y’all Need a Runninback?

2. What Is a Running back?
A running back (RB) is a position on a football team.
He usually lines up behind the linemen and the quarterback.
His job is to take handoffs and pitches, occasionally go out for passes, and to block for the quarterback.
He is also referred to as a tailback or halfback.

3. What We Want to Find
Is there a relationship between loss of production and turning 30 years old for NFL running backs?
Rushing Yards
Rushing Touchdowns
What is the average amount of Pro Bowls a running back makes?

4. How We Collected Data List of running drafted between 1995 and 2004
Assign each player a number
Randomly generate a number until we had a list of 50 running backs that met our criteria without any repeats

5. 1 Sample T-Test: Rushing Yards Difference (yards at 25-yards at 30)
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Ho: µrushing difference = 0 Ha: µrushing difference > 0
Conditions met -> t distribution -> 1 sample t-test
P(T > l df = 49) =
= 3.457
We reject the HO because our P-value of < alpha = .05.
We have sufficient evidence that the rushing difference between age 25 and 30 for running backs is greater than 0. This means running rush for more yards at age 25 than they do at age 30.

6. 1 Sample T-Interval: Rushing Yards Difference (yards at 25-yards at 30)
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Conditions met -> t distribution -> 1 sample t-interval
= ( , )
df= 49
We are 95% confident that the true difference in rushing yards between ages 25 and 30 is and yards.

7. Rushing Difference Graphs
Shape: unimodal, symmetric
Center: mean
Spread: (-869,1566)
Most running backs rush for about more yards when they are 25 than when they are 30.

8. 1 Sample T-Test: Rushing Touchdown Difference (touchdowns at 25- touchdowns at 30)
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Ho: µtouchdown difference = 0 Ha: µtouchdown difference > 0
Conditions met -> t distribution -> 1 sample t-test
P(T > l df = 49) = .0082
= 2.485
We reject the HO because our P-value of < alpha = .05.
We have sufficient evidence that the touchdown difference between age 25 and 30 for running backs is greater than 0. This means running rush for more touchdowns at age 25 than they do at age 30.

9. 1 Sample T-Interval: Rushing Yards Difference (yards at 25-yards at 30)
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Conditions met -> t distribution -> 1 sample t-interval
= ( , )
df= 49
We are 95% confident that the true difference in rushing touchdowns between ages 25 and 30 is and touchdowns.

10. Touchdown Difference Graphs
Shape: unimodal, roughly symmetric
Center: mean
Spread: (-20,20)
Most running backs score about 2.34 touchdowns more when they are 25 then when they are 30.

11. 1 Sample T-Test: Pro Bowls Made
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Ho: µpro bowls made = 1 Ha: µpro bowls made > 1
Conditions met -> t distribution -> 1 sample t-test
P(T > l df = 49) = .1
= 1.275
We fail to reject the HO because our P-value of .1 > alpha = .05.
We have sufficient evidence that running backs make 1 Pro Bowl during their career in the NFL.

12. 1 Sample T-Interval: Pro Bowls Made
State Check
1)SRS 1) Stated random
2) Pop ≥ 10n 2) All RB in history ≥ 500
3)Normal pop or n ≥ 30 3) n = 50
Conditions met -> t distribution -> 1 sample t-intevral
= ( , )
df= 49
We are 95% confident that the true number of Pro Bowls that a running back makes during his career in the NFL is between and Pro Bowls.

13. Pro Bowls Made Graphs Shape: unimodal, right-skewed Center: median - 1
Spread: (0,5)
Most running backs make about 1 Pro Bowl.

14. Rushing Yards Scatterplot
Formula: = + 300
Interpretation: rushing yards at 25 times .286 plus 300 = rushing yards at 30

15. Touchdown Scatterplot
Formula: = + 2.8
Interpretation: touchdowns at 25 times .116 plus 2.8 = touchdowns at 30

16. Who is this running back?
Age 25 Stats
Yards: 1298
Touchdowns: 12
Age 30 prediction
Yards:
Touchdowns: 4.192
Adrian Peterson

17. Who is this running back?
Age 25 Stats
Yards: 1364
Touchdowns: 11
Age 30 prediction
Yards:
Touchdowns: 4.076
Chris Johnson

18. Who is this running back?
Age 25 Stats
Yards: 1008
Touchdowns: 13
Age 30 prediction
Yards:
Touchdowns: 4.308
BenJarvius Green-Ellis

19. Who is this running back?
Age 25 Stats
Yards: 1515
Touchdowns: 18
Age 30 prediction
Yards:
Touchdowns: 4.888
Deangelo williams

20. Who is this running back?
Age 25 Stats
Yards: 1324
Touchdowns: 5
Age 30 prediction
Yards:
Touchdowns: 3.38
Maurice Jones Drew

21. Who is this running back?
Age 25 Stats
Yards: 1042
Touchdowns: 7
Age 30 prediction
Yards:
Touchdowns: 3.612
Steven Jackson

22. Application
Running backs are better statistically at age 25 than they are at age 30.
This means running backs should work to become productive earlier in their careers in order to obtain a large contract early.
The player might want to work harder than planned at age 30 so that they can improve their production.

23. Bias/Error
The running back got hurt during their season for being 25 or 30
The running back could have been a starter for one season and a backup for the other
The offensive line could have been better one year than it is the other.

24. Conclusion/Opinion
We would choose to have a running back age 25 on our team instead of a running back age 30
Running backs that are 25 score more touchdowns and gain more yards
They will also be in the league longer due to younger age
We found out running backs will make around one Pro Bowl in their career