The 2025 PDC World Grand Prix, kicking off on October 6 at Leicester’s Mattioli Arena, demands precision from the very first dart under its unique “double-in, double-out” format—a rule that could prove pivotal for world No. 2 Luke Littler in his bid for a first title. Unlike standard PDC events where legs begin with any dart, players here **must start each leg by hitting a double (or the bullseye) to begin scoring from 501**, adding an extra layer of difficulty that punishes inaccuracy and rewards consistency on opening throws. Littler, seeded second and facing Dutch youth star Gian van Veen in the first round, has thrived in standard formats but faces a steeper challenge here, where missing the double-in means a “bust” turn with no points scored, disrupting rhythm early.
The Double-In Rule: A Format Like No Other
Introduced since the event’s 1998 inception, the “double-in, double-out” (DIDO) structure requires:
– **Double-In Start**: The first dart of a leg must land on a double segment (e.g., D20, D16) or the bullseye to activate scoring. Miss it, and that dart scores nothing, and the turn passes without progress—turning the opener into a high-stakes gamble.
– **Double-Out Finish**: Standard across PDC majors, the leg ends on a double, but the double-in elevates the entire event’s difficulty, making it the only TV tournament with this twist.
– **Set Format**: Best-of-five legs per set (first to three legs), escalating to best-of-three sets in Round 1, with later rounds lengthening—testing endurance under the format’s pressure.
This “unusual” rule separates elite players, as missing the double-in can lead to “bust” turns and lost momentum—historically causing upsets, with defending champ Mike De Decker a surprise 2024 winner. Nine-darters are rarer here, as the double-in restricts combinations, with only three in tournament history (e.g., Brendan Dolan’s 2011 double-start perfect leg).
Littler’s Challenge: Adapting to DIDO
Littler, making his second Grand Prix appearance after a 2024 first-round loss to Rob Cross (2-0), enters as 7/4 favorite but faces scrutiny over the format. His explosive scoring (102+ averages) shines in standard play, but the double-in demands early precision—analysts like Paul Nicholson note van Veen’s “fearless” doubles could exploit any rust from Littler’s elbow recovery and PCOM skips (tied 58th, £21,000). Their 1-1 H2H (van Veen won a 2025 European Tour leg) adds intrigue, with Littler’s youth mirroring van Veen’s but format favoring the adaptable.
A victory opens paths to van Gerwen or Humphries, where DIDO mastery could fuel Littler’s Triple Crown chase (£1.5M+ earnings already).
Stakes and Viewing
The £600,000 event (winner £120,000) counts toward the Order of Merit, vital for Littler’s No. 1 push. Watch live on Sky Sports (UK), PDCTV globally, or Kayo/Fox (Australia)—Round 1 from 7 PM BST October 6.
Littler’s DIDO adaptation could define his legacy—master it, and the £120k trophy awaits.
