Daryl Mitchell believes the fine-tuning for the England and Wales Cricket Board's controversial 100-ball concept may be nearing completion.

The Worcestershire batsman is the chairman of the Professional Cricketers' Association and gave his backing to the tentatively-titled 'The Hundred' that is having its idiosyncrasies worked on by the ECB.

Six pilot days were commissioned earlier this month and the fourth at Trent Bridge was open to the media on Monday, giving an insight into how the new format – set to launch in the summer of 2020 – may eventually look.

While the rules and regulations have not been confirmed by the ECB, rumours have been circulating for some time about five-ball overs and changing ends after every 10 deliveries, provoking consternation in some quarters.

Both of these proposals were in effect in Nottingham for two 'North' v 'South' matches largely featuring second XI players from a number of different counties.

Mitchell played in the second fixture and was enthused that 'The Hundred' is similar to the Twenty20 format.

He said: "It's been interesting. The positive thing from my point of view is that it's still definitely cricket, which I was a bit sceptical about.

"In terms of skill-sets and things it's not very different to T20 cricket, which is a good thing.

"Obviously 100 balls is a pretty easy concept and everything goes up in blocks of five or 10.

"It's a little bit odd changing bowlers and not changing ends to start with but after two sets of 10 you got used to it, and it came naturally by the end of the day."

Once bowlers had completed a five-ball block, they had the option of sending down another five deliveries straight away – and could do so even if a change of ends was due.

However, each bowler was restricted to a maximum of 10 balls at any one time and 20 in total.

Further playing regulations included a powerplay – in which two fielders were allowed outside the 30-yard circle, as in the T20 format – to start the innings, while the fielding captain was able thereafter to call a strategic timeout.

The timeouts lasted up to two-and-a-half minutes, during which time the coaches were able to enter the fray, while fielding substitutes were also trialled.

Mitchell added: "We tried three different lengths of powerplay, and I think that needs sorting.

"The substitution thing needs looking at closely if they are going to implement that. It got a bit messy at times, but I think there's some merit in that, and it needs more (looking at).

"One thing they do need to get is a good signal for the end of five balls. Looking on from the side it was 'what's going on here?', because you don't count to five yourself.

"But we have (two more pilot days). Hopefully that will iron out a few things. But it's more a case of dotting the i's and crossing the t's. We are not far away from where we want to be."

Designed to attract a new audience to the game as well as offer a shortened product to appeal to broadcasters, there have been fears of how 'The Hundred' will impact the Vitality Blast.

Mitchell, part of Worcestershire's charge to the domestic sprint format title on Saturday, sees no reason for panic and thinks playing in the new competition could boost an individual's prospects of featuring in lucrative franchise T20 leagues overseas.

He added: "The Blast as we know it isn't going to change. Edgbaston will still be packed to the rafters (on Finals Day). It's something for current county supporters to look forward to.

"T20 Blast is something where I still expect Worcester to be packed on a Friday night full of four or five thousand people.

"I certainly hope they can live in tandem and both work together and this is an add-on to the Blast.

"I see (The Hundred) as a vehicle for the lads to go round the world and play in other domestic T20s, and also into T20 internationals."