By John Clayton ESPN.com Smith Cardinals coach Dennis Green's decision to start Emmitt Smith over Marcel Shipp has a lot to do with choosing running left over running right, a West Coast offense trait Green learned from his mentor, Bill Walsh. To do this, Green has switched Leonard Davis from right guard to left tackle, which fits the natural ability of the left-handed Smith to run left. According to Stats Inc., most of Smith's 17,438 yards were up the middle, but Smith has gained 5,569 yards running left, 1,930 more than on runs to the right. Green said O.J. Simpson and Jim Brown also were successful southpaw runners. Tick, tick, tick Bills coach Mike Mularkey is using an on-the-field clock to remind the inner clock in Drew Bledsoe's head to release the ball quicker, but Bledsoe's best learning tools may be the hands of running backs Travis Henry and Willis McGahee. The Bills completed only 60 passes to running backs last season, 33 fewer than in 2002. Henry and McGahee are excellent receivers and using them more in the passing offense is one way to cure Bledsoe's tendency to hold on to the ball. Speed it up The most noticeable difference in the Tampa Bay offense minus the departed Keyshawn Johnson and holdout Keenan McCardell is speed. Joey Galloway still runs 4.3 or faster, and rookie Michael Clayton brings fresh young legs. Also, Charlie Garner's quickness out of the backfield adds explosiveness. The Bucs' 10.7 yards per catch last season ranked in the bottom seven. Not surprisingly, those seven teams had losing records. Kimball to the rescue The Colts rookie who could make the biggest impact is Penn State kicker David Kimball, drafted in the seventh round for kickoffs. Because their offense is so good, the Colts kicked off a league-high 99 times last season. However, teams on average started drives on their own 29-yard line because of the Colts' short kickoffs. In mini-camps, Kimball consistently boomed unreturnable kickoffs. With Pro Bowl kicker Mike Vanderjagt, the Colts are set for field goals and extra points, but Kimball should give them a big edge in field position. John Clayton is a senior writer for ESPN.com.