Observation deck: Lions could be explosive

ALLEN PARK, Mich. -- Five observations from Detroit Lions training camp, gleaned from the team's Thursday practices:

1. Lethal weapons The Lions' offense will be better once the season starts. The reason is Calvin Johnson. Having options such as Roy Williams and Mike Furrey allowed Jon Kitna to throw for 4,208 yards and 21 touchdown passes last season. Johnson will allow the Lions to get maximum value out of three-receiver sets. Last year, teams bracketed Williams and Furrey, forcing Kitna to look elsewhere for completions in those formations. Less than 50 percent of Kitna's passes, and less than 50 percent of his completions in three-receiver sets, went to Williams and Furrey.

Johnson will give offensive coordinator Mike Martz the ultimate three-receiver set. Johnson will be the movement receiver, the flanker who will move from left to right and right to left. Williams, who has improved dramatically on his release away from defenders at the line of scrimmage, will stay as the split end and impose his physical presence on pass defenses. Furrey will work the middle of the field and pull safeties away from the outside receivers.