The first important thing to know is Jennings has been thrown at much more than Tillman. He has been targeted 80 times, Tillman 50.
Considering Tillman frequently has been matched against the opponents' best receivers, that target number tells us opposing quarterbacks are shying away from him.
But they are connecting a greater percentage of passes thrown his way. Tillman's "burn percentage" is .620, compared to .463 for Jennings.
Jennings has 18 passes defended and eight interceptions compared to eight and two for Tillman, so he clearly has been more aggressive going after the ball.
But when opponents connect, they have had bigger gains against Jennings. They have averaged 13.5 yards per completion at Jennings, compared to 10.4 at Tillman. Jennings also has been beaten for two touchdowns; Tillman has yet to give up one.
Of course, Tillman has forced seven fumbles and Jennings none.
Front office chess: Punting Podlesh
Wednesday the Bears worked out four punters — Spencer Lanning and Ryan Quigley, each of whom had been with the team in previous offseasons, and Chas Henry and Ryan Tydlacka.
This clearly is an indication the team is less than thrilled with the recent performances of Adam Podlesh, who ranks 30th in the NFL in punting average (41.7) and 21st in net average (38.4).
The workouts gave the Bears an idea of where each of the free agent punters are currently from an ability standpoint. If they have to make a move, they now know who they like the best.
But cutting Podlesh would be a last resort, because the Bears made a significant investment in him.
Before the 2011 season, they signed him to a five-year, $10 million deal. They gave him $2 million to sign and guaranteed him $3.5 million.
If the Bears cut Podlesh this season, they will take a $1.4 salary cap hit in 2013 for a punter who isn't even on their roster. And they will use up more cap space for another punter.
It's not a pretty picture. So Podlesh's contract may help him stay employed.
If he continues down his performance path, however, no contract is going to save him. That was the message that was sent Wednesday.