The helter-skelter nature of Twenty20 cricket hardly affords batsmen the luxury of seeing off the opposition’s most dangerous bowler, but when Gloucestershire and Kent set out in their respective matches on finals day at Edgbaston on Saturday, the temptation to do precisely that will be understandable.

Spinners have been all the rage in the game’s shortest format, and that suits their semi-final opponents, Lancashire and Sussex, just fine.

Because while Lancashire will be able to unleash Muttiah Muralitharan, who is almost certain to pass Shane Warne to become Test cricket’s leading wicket-taker in the next few months, against Gloucestershire, the county champions, Sussex, have Mushtaq Ahmed’s bubbly leg-breaks up their sleeve for the second semi-final against Kent. Between them, the subcontinental spinners could well bowl the eight overs that determine the finalists.

The value of Murali and Mushy hardly needs elaboration, but two moments in their sides’ progress to the last four sum things up. For Mushtaq, one over was enough. Sussex needed to beat Surrey in their penultimate group match at The Oval to make it to the knockout stages for the first time since the Twenty20 Cup began in 2003. The game had been reduced to five overs a side by the Kenning-ton gloom, and Surrey were 25 for one off two overs chasing 66 to win when Mushtaq came on to bowl his allotted over. His first delivery persuaded James Benning to miscue a slog-sweep to deep backward square. His sixth, a slider, bowled Rikki Clarke. Mushtaq’s cool-headed analysis of 1-0-8-2 turned out to be the matchwinner.

Muralitharan’s moment came in the quarter-finals against Warwickshire at Edgbaston. In a match in which only one other bowler on either side conceded fewer than seven an over, Murali finished with figures of 4-0-18-4 to inspire Lancashire to a six-run victory. Because of international commitments with Sri Lanka, that represents his only Twenty20 outing of the season so far. But what an outing.

None of the four counties involved on Saturday has lifted the Twenty20 Cup before. In fact only Lancashire have made it to finals day: in 2004 they lost in the semi-final to Surrey at Trent Bridge; in 2005 they were brushed aside in the final by Graeme Smith’s Somerset at The Oval. But the occasionally unfathomable art of Mushtaq and Murali makes it more probable that the new name on this year’s trophy will be either Sussex or Lancashire.

When the Sussex coach Mark Robinson points out that Mushtaq is “a very good bowler when people are trying to get after him”, he is not kidding.

Among bowlers who have sent down at least 30 overs in the five years of the competition’s history, Mushtaq is the sixth-most economical. His runs-per-over ratio of 5.91 places him behind only Stuart Broad (an outstanding 4.91), the retired Gloucestershire left-arm seamer Mike Smith (5.17), Carl Hooper (5.79), Chris Schofield (5.85) and Jimmy Ormond (5.88). In short, he will be the meanest bowler on show at Edgbaston. But then Mushtaq’s excellence has hardly come as a surprise, and Robinson points to other factors in Sussex’s ascent to the last four.

“There has been evolution going on at the club. This season we’ve had no Mike Yardy, who was our s e c o n d - h i g h e s t runscorer in the competition last year, and no Matt Prior, who has been our best batsman since the tournament began. So we’ve given a chance to three youngsters – Ollie Rayner, Luke Wright and Chris Nash – and two of the three have taken it. Wright and Nash have been outstanding at the top of the order. They’ve been a revelation.”

Robinson also points to contributions from Chris Adams (214 runs at 42.8 in this year’s tournament) and Murray Goodwin (264 at 37.7), whose combined age of 71 belies the theory that Twenty20 is a young man’s game. And he highlights the canny signing of another Pakistani spinner, Saqlain Mushtaq, who has made an instant impact with his measured off-breaks.

“We’ve given people roles and had a team plan,” says Robinson. “It’s freed up a couple of the senior players and we’ve encouraged the youngsters to be brave. We’ve taken away the fear of failure. We had a bad defeat in our opening game against Essex and we took a lot out of that. Now we’re just excited. We had a big day out at the C&G Trophy last year and we loved the buzz and the excitement. It’s made us hungry for more.”

Gloucestershire and Kent will have their own views on the matter, but a Sussex-Lancashire final would be a microcosm of last year’s race for the County Championship, won in the end by Robinson’s men.

But in 2006 Lancashire did not have Muralitharan, who was touring England with Sri Lanka. Now, as their Aussie-turned-Pom Stuart Law points out, they possess a bowler capable of “causing carnage”, even in a 20-over slog.

Law also believes that Murali’s presence helps take the pressure of Gary Keedy, the underrated slow left-armer who has conceded only 5.15 runs an over this season.

“Keedy has bowled as well as anyone in the competition,” says Law. “He’s not to be underestimated. It can also be a help to him if batsmen concentrate on Murali at the other end and relax a bit when Keedy comes on. He’s learnt how to bowl in Twenty20 cricket and holds his nerve well.”

Law missed finals day in 2004 through injury and fought a lone hand in the 2005 final, making 59 off 45 balls in a below-par Lancashire total of 114 for eight in 16 overs. And while that experience has sharpened his focus, his attitude to Twenty20 cricket retains a healthy perspective.

“Twenty20 is just an opportu-inity to go out and express yourself,” he said. “Natural flair comes into play. It doesn’t suit the guys who are a bit more manufactured, because you have to react quickly to certain situations and be able to play two or three shots to every ball. There’s no special formula.

“You can’t really plan for it. It’s true that Leicestershire seem to have an out-and-out plan and they’ve reached a few finals, but it’s a case of enjoying the day and not thinking too much about it.”

The batsmen of Gloucestershire and Kent might be advised to adopt a similar approach.

Twenty20 finals day

Semifinals, Edgbaston Lancashire v Gloucestershire 11.30am

Sussex v Kent 3pm

Followed by final at 7.15pm

TV coverage Sky Sports 1, next Saturday, 10.30am until 10pm