Surrey leaning on Roy for glory

Good one-day pedigree and a sizeable playing budget should be a recipe for T20 success but Warwickshire have struggled since their appearance in the inaugural final. They lost in six quarter-finals between 2004 and 2010 but the last three years have been a flop. So it was time they came good again and this year their bowling attack has been their real strength - Rikki Clarke, Jeetan Patel and Ateeq Javid have all conceded their runs at less than a run-a-ball - and in Varun Chopra and Will Porterfield, they have given their attack just enough runs to play with.

Key Man
Spin has long been considered the crucial factor in a T20 bowling attack and in Jeetan Patel, Warwickshire have a star. Patel has been the best bowler in the competition - the second-highest wicket-taker with 23 scalps and, perhaps more importantly, the third-best economy rate of bowlers to have played 10 matches or more this season. Patel has strangled the life out of many a batting order this season, none more so than Essex in the quarter-final.

How they qualified
Warwickshire's T20 woes looked set to continue after four straight defeats in the middle of qualifying but they rallied to win their final three matches to sneak through as the fourth-placed side in the North Division. Handed perhaps the toughest quarter-final, away to Essex, they produced a memorable performance, making their highest total of the season, and caused the shock of the round.

Odds: 7/2

Having dominated the early editions of the competition - reaching the first four Finals Days and winning the Cup in 2003 - big-spending Surrey regressed and finished bottom of the South Group in 2012. Last season saw a revival before their hammering to Northamptonshire in the final and the form has carried through to 2014. But their success has relied rather too heavily on Jason Roy's runs - Gary Wilson is the only other batsman in their squad to average over 25. Kevin Pietersen flies back in time to play but has not found his form. Tillakaratne Dilshan was Surrey's best bowler through qualifying but he is unavailable for Finals Day and the seam attack have struggled to find consistency.

Key Man
Everyone is talking about Jason Roy. He is perhaps the hardest hitter in the county game and crucially this season has married raw power with some nous to spend longer at the crease. Roy is the leading run scorer in the competition with 619 runs at 47.61 and a strike-rate of just over one-and-a-half runs per ball. If Roy fires again, this could be Surrey's year.

How they qualified
Beside two comfortable defeats to Essex, Surrey strolled through qualifying to secure second place in the South Division. Their quarter-final against Worcestershire was a poor match, with Surrey making a meal of a small chase.

Odds: 9/4 joint-favorites

The Red Rose have been there or thereabouts in every season of T20 but this is their first Finals Day since 2011. They were the pace-setters in this season's qualifying with 10 wins from 12 completed matches. Twice Lancashire posted totals over 200, including the competition's best 229 for 4. Greater than the sum of their parts, the batting has been a team effort with consistent contributions from the likes of Karl Brown, Paul Horton and Tom Smith, who found success as a pinch-hitter. Kabir Ali and Junaid Khan were the standout bowlers but Junaid is unavailable for Edgbaston.

Key Man
Steven Croft has been a solid part of Lancashire's success with middle order runs and tight spells with his offspin, often opening the bowling, claiming 11 wickets. Typical of Lancashire's squad: more-than-handy contributions without producing eye-catching stats.

How they qualified
Lancashire won the North Division with plenty to spare but were given a rattling in the quarter-final against Glamorgan that was heavily affected by the weather. Jordan Clark's outrageous treble-wicket maiden turned the match and Lancashire scraped through by a run after a poor batting performance.

Odds: 3/1

This lot again, eh? Hampshire have become the T20 kings. This will be their fifth consecutive Finals Day appearance, a run that includes titles in 2010 and 2012. Previous success was masterminded by Dimitri Mascharenas, with South African Neil McKenzie providing an essential middle-order role; with both players leaving the club last season, a major hole was left. But Hampshire have coped and James Vince, at 23, has ensured their T20 run has continued, not least with his own form: 398 runs at 30.61. Owais Shah - who returns for Finals Day - has been a handy signing; Will Smith too, with 17 wickets in qualifying.

Key Man
Danny Briggs may have failed to convince on the international stage but in domestic one-day cricket he continues to be a fine performer. He has been Hampshire's leading T20 wicket-taker in three of the last four seasons and once again leads their tally with 21 scalps at 19.14.

How they qualified
Hampshire once again found qualification no issue with nine wins in the South Group but missing out on a home quarter-final by 0.29 of a run looked to be costly with an away quarter-final to Nottinghamshire. Cue Hampshire's best batting performance of the season, led by James Vince's 93 not out, to chase 198 with an over to spare.

Odds: 9/4 joint-favorites