Image source, Getty Images

Northants Steelbacks, the 2013 winners, boast a powerful batting line-up for their game at Durham. They include debutant Shahid Afridi, who has a stratospheric career strike-rate of 154.37 in the game's shortest format. The Jets will look to the likes of skipper Mark Stoneman and Scotland's Callum MacLeod to give them a flying start to their innings.

Durham: Stoneman (capt), Mustard, MacLeod, Collingwood, Muchall, Pringle, Borthwick, Jennings, Hastings, Arshad, Rushworth.

Northants: Wakely (capt), Levi, Cobb, Willey, Shahid Afridi, Kleinveldt, Rossington, Keogh, Crook, White, Stone.

Northants won the toss and opted to field first - listen to live commentary via the Live Coverage tab.

BBC Radio Bristol's Bob Hunt at Bristol:

"Gloucestershire are on the back of a superb championship win against Lancashire at Old Trafford - six of that team are in the side this evening."

The teams have been announced for Gloucestershire's home game against Middlesex at Bristol, with Aussie batsman Joe Burns making his debut for the visitors. He has a none-too-shabby T20 career strike-rate of 122.73, with a best score of 81 not out. The home side will be skippered by Ian Cockbain, with Michael Klinger not due to arrive until after their first two matches.

Gloucestershire: Dent, Cockbain (capt), Handscomb, Marshall, Jones, Noema-Barnett, Howells, Taylor, Fuller, Payne, Taylor.

Middlesex: Stirling, Compton, Burns, Voges, Franklin (capt), Dexter, Simpson, Harris, Finn, Podmore, Patel.

Gloucestershire won the toss and opted to field first - listen to live commentary via the Live Coverage tab.

England Women all-rounder Danielle Wyatt: "Buzzing for the start of the @NatWestT20Blast that starts tonight under the lights at Headingley! Set to be a cracker of a tournament!"

Image source, Getty Images

Four years after retiring, Andrew "Freddie" Flintoff returned to action with Lancashire Lightning and helped his county reach the final.

However, there was no fairytale ending for the ex-England all-rounder, despite dismissing former international team-mate Ian Bell in the third over against Birmingham Bears.

Birmingham's Laurie Evans hit a barnstorming 53 off 30 balls and that was followed up by 3-31 from Oliver Hannon-Dalby, as The Bears earned a four-run victory that gave them their first T20 title.

Image source, Getty Images

With a new name, a new format and new groups, last year's T20 Blast had plenty of memorable moments.

Luke Wright's sensational unbeaten 153 of 66 balls for Sussex Sharks against Essex Eagles, which included 11 sixes, proved that English players definitely know how to clear the ropes.

Dirk Nannes, who turns 39 tomorrow, was the leading wicket-taker with 24 for Somerset, but it was another veteran who provided the story of the competition....

Image source, Joe Townsend/BBC Sport

You can listen to ball-by-ball coverage of every match in this season's T20 Blast from BBC local radio stations via the BBC Sport website - commentaries are available on desktop, tablet and mobile devices.

In addition, BBC Radio 5 live sports extra will provide commentary of a selected match each Friday, while you can also follow a live text commentary of every set of Friday fixtures during the group phase.

And if you miss any T20 Blast action, there's a weekly podcast to help you catch up.

There are eight matches in all tonight.

Durham face Northants and Gloucestershire take on Middlesex in our two 17:30 BST starts.

Then at 18:30 BST there are three more games - our featured match is Nottinghamshire Outlaws v Birmingham Bears.

Our final three games get under way at 19:00 BST and six more teams - including last season's semi-finalists Hampshire - open their T20 Blast campaigns.

In all, 18 counties are hoping to emulate Birmingham Bears, who won the tournament in 2014.

This year's semi-finals and final are at Edgbaston on 29 August.

Who will put their name on the trophy this time around?

For the next few weeks - well, on Friday nights at least - prepare for some crash...

Image source, Getty Images

...bang...

Image source, Getty Images

...and wallop...

Image source, Getty Images

The T20 Blast is back.