Our colleagues at the SEC blog are examining how many of each team's returning tacklers are back and which are gone, and we'll do the same here this week.
These numbers don't guarantee success (even bad defenses have to make tackles eventually), but you can in some ways guarantee some progress.
So who's coming back from where? Let's look closer. We'll examine the bottom half of the Big 12 alphabet later this week.
Safety Ahmad Dixon also returns with 102 tackles, but he played mostly nickelback last season. He's moving back to traditional safety to help replace Mike Hicks and Chance Casey, who are both gone from last year's team. They combined for 147 tackles.
Defensive linemen Terrance Lloyd and Chris McAllister are both returning as the team's top returning tacklers on the front line of the defense. Eight of Baylor's top 10 tacklers return overall, and nine of the top 12.
Top tackler A.J. Klein is gone, and so is fellow linebacker Jake Knott. Klein had 117 tackles, and Knott might have had just as many if knot for a shoulder injury that ended his season prematurely. Three of the Cyclones' top five tacklers are gone.
Linebacker Jeremiah George had his role increase after Knott's injury and returns for his senior season after making 87 stops.
Overall, just five of Iowa State's top 12 tacklers return.
The good news? Top tackler Ben Heeney, a speedy linebacker, returns after making 112 tackles, 20 more than any other Jayhawk.
Linebacker Huldon Tharp (54 tackles) was scheduled to return, but he chose to end his career, meaning five of KU's top seven tacklers are gone. Defensive back Lubbock Smith and defensive lineman Toben Opurum are the other two who are gone.
KANSAS STATE (word of warning, this ain't pretty)
K-State returns the fewest starters of anyone in the Big 12, so you know this will get thin. Seven of Kansas State's top nine tacklers are gone. Only safety Ty Zimmerman and cornerback Randall Evans return.
All in all, 11 of Kansas State's top 15 tacklers will not return from last year's defense, which ranked second in the Big 12.
Starting linebacker Tre Walker will be back, but he made just 19 tackles last season and suffered a knee injury in midseason and finished 16th on the team in tackles.
Cornerback Aaron Colvin is the only one of Oklahoma's top five tacklers who will return in 2013, thanks to a couple early exits.
Overall, just six of Oklahoma's top 18 tacklers will return in 2013.