As free agency is set to begin, there will never be a class like '01 Patriots

2003 free-agent signing Rodney Harrison (center) and 2001 signee Mike Vrabel (right) helped the Patriots win three Super Bowls in four years in the early 2000s. Brian Bahr/Getty Images

FOXBOROUGH, Mass. -- With free agency set to begin at 4 p.m. ET on Wednesday, the New England Patriots aren't expected to be one of the NFL's busier teams.

Part of that is tied to having a core of up-and-coming defenders whose contracts expire after the 2016 season -- linebackers Jamie Collins and Dont'a Hightower, defensive ends Chandler Jones and Jabaal Sheard, and cornerback Malcolm Butler, among others. If the Patriots are going to spend big, it will most likely be on their own players, not those from another team.

So let's lead off the day with a little fun, ranking the best free-agent classes in the Bill Belichick era (2000-present):

1. 2001. A remarkable haul that included cornerback Terrell Buckley, guard Mike Compton, linebacker Bryan Cox, fullback Marc Edwards, quarterback Damon Huard, linebacker Larry Izzo, receiver David Patten, linebacker Roman Phifer, defensive end Anthony Pleasant, running back Antowain Smith, and linebacker Mike Vrabel. It's hard to imagine there will ever be another free-agent class in New England that has the impact of '01.

2. 2003. Safety Rodney Harrison is one of the team's best free-agent signings in history, which brings '03 up the ranks. Cornerback Tyrone Poole and linebackers Rosevelt Colvin and Don Davis also contributed in important roles.

3. 2014. Cornerbacks Darrelle Revis and Brandon Browner helped transform the defense for a year, while receiver Brandon LaFell had a career season and safety Patrick Chung revived his career.

4. 2011. The Patriots got a lot out of defensive ends Andre Carter and Mark Anderson, as well as safety James Ihedigbo and guard Brian Waters.

5. 2007. While linebacker Adalius Thomas ultimately proved to be not worth it from a big-picture perspective, he contributed in the '07 Super Bowl berth, while running back Sammy Morris, receiver Donte Stallworth and tight end Kyle Brady made some plays.

6. 2013. The duo of receiver Danny Amendola and defensive tackle Tommy Kelly made the biggest contributions, while Tim Tebow brought the headlines.

7. 2015. Sheard is the cream of the crop, while tight end Scott Chandler was a miss. Linebacker Jonathan Freeny did his part.

8. 2000. Defensive end Bobby Hamilton, punter Lee Johnson, cornerback Otis Smith and offensive tackle Grant Williams contributed.

9. 2004. Defensive tackle Keith Traylor and punter Josh Miller were top signings.

10. 2002. Tight end Christian Fauria was a big signing, while safety Victor Green and defensive tackles Rick Lyle and Steve Martin came aboard.

11. 2009. They got one good year out of cornerback Leigh Bodden, and defensive end Rob Ninkovich was a steal at the start of training camp and could count in this exercise. But running back Fred Taylor, receiver Joey Galloway, cornerback Shawn Springs and tight end Chris Baker didn't pan out.

12. 2006. Receiver Reche Caldwell led the team in catches, while linebacker Junior Seau brought an inspirational presence.

13. 2012. Receiver Brandon Lloyd and defensive end Trevor Scott made some plays, while defensive tackle Jonathan Fanene never played a game despite being an early target in free agency.

14. 2005. Receiver David Terrell and linebackers Monty Beisel and Chad Brown never really made their mark.

15. 2010: A quiet year, with tight end Alge Crumpler the one notable signing.

16. 2008. Very little to show for this class, as it was a year in which several low-budget cornerbacks were added: Fernando Bryant, Lewis Sanders, Jason Webster and Deltha O'Neal.