Read our preview of all nine teams in the North Group.
Overseas player: Jesse Ryder
The perfect blend of youth and experience just added mercurial brutality in the form of Jesse Ryder. Disconsolate after last year's semi-final defeat to Surrey - they were away from Edgbaston barely an hour after their loss - fortress Chelmsford might rock off its foundations with these Friday night fixtures. The loss of Owais Shah's know-how and wrists means someone, perhaps Ravi Bopara, will need to bat higher and longer.
Overseas player: Jacques Rudolph
That there isn't more made about Chris Cooke is no slight on him or Glamorgan. But, at 27, the onus is on him to take a competition by the scruff of its neck and showcase his destructive capacity. He is surrounded by more than capable team-mates - Jim Allenby, in particular - but it is the amazing that gets you ahead in T20 cricket. Cooke is capable of enhancing his stature by doing just that.
Overseas player: Michael Klinger
"A good honest club" usually translates as "don't expect much" and, while they are the former, it would be foolish to assume the latter despite beginning the tournament with a two-point penalty. Michael Klinger is a manufactured yet very effective short-form batsman - fifth highest run-scorer in last years' tournament. Tavaré is a name associated with long days of batting but how will Will take to a short dash?
Overseas player: Kyle Abbott, Glenn Maxwell
A strong bet for the final four given they have appeared in the last four Finals Days, winning in 2010 and 2012. But they now have to begin life without Dimitiri Mascharenas, who masterminded so much of that success. Neil McKenzie has said goodbye too. New leader James Vince has plenty to live up to but expect his captaincy to bear all the hallmarks of Hampshire's long-successful brains trust. He has the finest game-changer around in Glenn Maxwell, giving Hampshire the look of a perfect side.
Overseas player: Doug Bollinger
Rob Key's return as captain has given Canterbury a lift and performances so far have reflected as much. Doug Bollinger, both as a bowler and a character, has instilled a new sense of belief at the club. Mitch Claydon, having impressed during a handful of T20 games last year while on loan, will make a bigger impact this time around. And with Darren Stevens, anything is possible.
Overseas player: Dan Christian
Only a fool would attempt to pin down what Middlesex are about with the bat. The skill is there but the application, in all forms, is flaky. Dan Christian disappointed for Gloucestershire last year, but the Australian summer saw him earn a recall to the national side thanks to 543 runs and 19 wickets for Brisbane Heat. Eoin Morgan captains the side. Steven Finn will relish a shortened workload and a license to tear in.
Overseas player: Alviro Petersen, Dirk Nannes
Despite talk of decline and tossing out the old, Somerset have enjoyed a good start to the season. No one symbolises that more than Marcus Trescothick, who has rediscovered his mojo. While Craig Kieswetter's international career is far from over, it is likely he will not be called upon during the summer, allowing him to build on his emphatic 517-run campaign last year. Dirk Nannes comes in having proved he has a handle on his injuries with eight matches and an economy rate of just above seven in the recent edition of the BBL. Peter Trego, as ever, is a showstopper.
Overseas player: Graeme Smith, Robin Peterson
A young team finding their feet but perfectly capable of holding their own, and then some. Box office and effectiveness come in the form of Kevin Pietersen and Kevin O'Brien, both of whom have their availability limited by the Caribbean Premier League. The kids are alright, but here is an opportunity to improve on last year's finish as defeated finalists and be the best.
Overseas player: Steve Magoffin, Yasir Arafat
The return of Yasir Arafat, the leading wicket taker in English domestic T20 cricket, will have Sussex dreaming of replicating former glories. With him, they won the competition in 2009, qualifying for the Champions League in the process. Now based in Kent, he will be available for the entirety of the group stages. Surround him with Ed Joyce, Luke Wright and maybe even a bit of Matt Prior and Chris Jordan, and you have one heck of a side.