If it was being judged by baseball standards the Lions defense would look pretty good heading into training camp. It is strong up the middle. In Ndamukong Suh and Nick Fairley they have potentially as disruptive a defensive tackle tandem as there is in the game. Middle linebacker Stephen Tulloch played on a bulky knee last season and though his overall effectiveness waned he still led the team in tackles. By all accounts he’s completely healthy now and prepared to be the full-fledged leader of this unit. And the signing of free agent safety Glover Quin should provide the reliable stabilizing play-making presence on the back end the Lions have lacked since Louis Delmas’ knee issues popped up two seasons ago. But as bold and strong up the middle as this defense may be it is still a little sketchy on the edges. The defensive line may well sink or swim on the development of young unproven players like rookies Ziggy Ansah and Devin Taylor as well as four-year veteran Willie Young. One of the best position battles in camp will be for the left outside linebacker spot a position being contested by three unproven players — Ashlee Palmer Tahir Whitehead and Travis Lewis. And in the secondary most likely will feature a rookie (Darius Slay) and two second-year players (Bill Bentley and Jonte Green) playing major roles at right corner and nickel. The Lions were 27th in points allowed last season and were an abysmal 30th in turnover ratio. They forced just 17 turnovers. Only five teams were less disruptive than that. So the point of emphasis in the offseason was finding defensive playmakers players who got their hands on the ball. If you look at the defensive end position now it features Ansah at 6-foot-5 Taylor at 6-7 free agent signees Jason Jones at 6-5 and Israel Idonije at 6-6 and Young at 6-4. The Lions have changed their tune here. They used to sneer at batting down passes at the line of scrimmage; treating them like failed sack attempts.