There's a certain statistic that's nearly impossible to fool. You succeed in this area, you're going to win. You don't, and you're going to lose.
Allow me to prove it to you.
Here are the top four teams in this given statistic:
1. Cincinnati -- 5-0
2. Kentucky -- 5-0
3. Alabama -- 5-0
4. South Florida -- 4-0
Overall: 19-0
Pretty impressive, right? Now let's expand it to the top 10:
1. Cincinnati -- 5-0
2. Kentucky -- 5-0
3. Alabama -- 5-0
4. South Florida -- 4-0
5. North Texas -- 4-1
6. Florida* -- 4-1
7. UCF -- 4-0
8. Miami -- 4-1
9. Appalachian State -- 3-1
10. Michigan -- 4-1
Overall: 42-5 (*lost only to another team within the group)
Now let's do the top 20:
1. Cincinnati -- 5-0
2. Kentucky -- 5-0
3. Alabama -- 5-0
4. South Florida -- 4-0
5. North Texas -- 4-1
6. Florida* -- 4-1
7. UCF -- 4-0
8. Miami -- 4-1
9. Appalachian State -- 3-1
10. Michigan -- 4-1
11. Utah* -- 2-2
12. Notre Dame -- 5-0
13. Colorado -- 4-0
14. UAB -- 3-1
15. Auburn -- 4-1
16. Utah State -- 3-1
17. Minnesota -- 3-1
18. Washington* -- 4-1
19. Georgia -- 5-0
20. Washington State -- 4-1
Overall: 79-13, with only nine losses to teams outside the group
In fact, if you expand the group to the top 30, its record is 107-26 with only two teams under .500. Continue to zoom the frame out and you'll find only four of the top 48 teams sport losing records thus far.
Now let's look at the stat from the opposite end. Here are the bottom five teams in this given statistic:
130. Rice -- 1-4
129. Connecticut -- 1-4
128. Louisiana-Lafayette -- 1-3
127. UTSA -- 2-3
126. Colorado State -- 1-4
So the top five teams are 23-1, and the bottom five are 6-15.
Clearly, this is a statistic that can't be fooled. Succeed here and you're going to win, fail and you'll lose.
And before you ask, no, it's not turnover margin. It's still a great pathway to winning (or losing), but turnover margin can be fooled, at least so far this year. Kansas has the best turnover margin in the nation despite a 2-3 record. TCU has the nation's fifth-worst turnover margin, and the Frogs are 2-3.
So... what is it?
It's pass efficiency defense.
Here is the top 10, via CFBStats.com.
And the top 20.
Minimum entry to this group -- No. 20 Washington State -- limits opposing passers to an average game of 13-of-26 passing for 154 yards with a touchdown and an interception. The best -- No. 1 Cincinnati -- holds opponents to 16 or 17 completions on 34 attempts for 159 yards, with 0.6 touchdowns and 0.8 interceptions per game.
Is this the only way to win? Of course not. The top 20 teams in scoring are a combined 76-18. The 24 teams that average at least a plus-1.0 turnover margin are a collective 82-25.
But successfully, efficiently defending the pass is the most foolproof way to winning games.