Christopher Kempf, the stats analyst of the PDC, looks at the unique features of the BoyleSports World Grand Prix which make the event one of the most exciting on the calendar.
This weekend, Michael van Gerwen will arrive in Dublin with the goal of doing something that no player has done in the past decade: win the World Grand Prix in two consecutive years.
While Van Gerwen hoisted the title four times in that span of ten years, he has never successfully defended any of those victories, and those three previous attempts all ended in remarkable ways.
In 2013, he suffered his last televised loss to Dave Chisnall to date; in the next 26 successive matches between the two, Chizzy has been winless. In 2015, Robert Thornton thwarted the Dutchman in a thrilling final. And finally, Van Gerwen was dumped out of the 2017 Grand Prix in a deciding leg by John Henderson, who inflicted upon the world number one his first loss in the first round of a televised ranking event since 2011.
The fact that a player of Van Gerwen's calibre has repeatedly failed to repeat as the champion indicates that the World Grand Prix rewards players with the best timing rather than the most skill, and presents the leading players in the world with a fearsome minefield of obstacles on the road to claiming the title, let alone to a repeat triumph.
The Double-Start Format
The most obvious unusual aspect of the World Grand Prix is the basic game itself, in which no leg can be completed without hitting both a double to start and a double to finish.
Players occasionally throw several exasperated fistfuls of darts at a double to try to "get in", scoring zero points along the way, while their opponent spears the double in his first visit and runs away with the leg.
Only rarely would you see a comeback such as Mark Dudbridge's in 2007 in that dramatic deciding leg against Andy Jenkins, when the Bristol thrower missed nine starting doubles but snatched victory in 12 scoring darts.
The difficulty of this format, at first glance, is obviously mental; straight-start 501 presents players with an environment in which missing a target still scores points and gets a player closer to zero. This is not true of the opening few throws of a World Grand Prix leg if the player can't find the double; often he is resigned to watching his opponent's lead increase rapidly.
One of the more subtle effects of double-start is to reduce the advantage of throwing first in a leg. The benefit of doing so is still substantial - in the World Grand Prix, the player with the first doubles attempt of a leg wins it in the end 58% of the time - but it is still a 25% smaller advantage than would be had in a typical straight-start event.
A player's choice of double poses an interesting conundrum. The long-run doubles data indicates that players typically hit double 16 about three times per 100 more often than they do double 20, and that this double would provide the highest probability of a successful double start.
Indeed, several well-known double 16 adherents - such as Simon Whitlock and Mervyn King - start almost all World Grand Prix legs with attempts at double 16.
But doing so precludes the possibility of completing the elusive double-start nine-dart finish, a feat which has been accomplished only three times in the history of the event.
With a record 42 perfect legs in straight-start format having been completed so far this year, the prestige of being the first player since 2014 to complete a perfect leg at the World Grand Prix grows apace.
Starting on double 16 also lends itself better to attempts at treble 19 in the starting visit rather than treble 20, such that a perfect visit along these lines scores 14 points fewer than a perfect visit of 160 scored by hitting treble and double 20.
But on the other hand, double 20 is more frequently missed to the inside than any other double; many players who prefer double ten are accustomed to aiming slightly more to the inside than they would at other doubles.
In double-start, however, missing to the inside can block further attempts at tops, necessitating an unwelcome switch, while double 16 fans are far more likely to stick with that double, regardless of where their misses land.
The Sets Format
Compounding the randomizing effects of double start is the set format, well-known for thwarting the best efforts of players who, in a straight-legs format, would otherwise have won the match.
Consider the 2015 final, in which Michael van Gerwen threw twice as many 180s, averaged six points higher and won four legs more than Robert Thornton, but lost the match.
The trouble for Van Gerwen is simply that he won eight of his 20 legs at the wrong time by failing to win any of the set-deciding legs in the final.
In addition, the World Grand Prix differs from that other set-format tournament, the World Championship, in that there is no requirement to win a tie-breaking set by two clear legs; the player who wins the right to throw first in the match earns that crucial 58% advantage in a deciding leg of the match.
The First Round Hurdle
Finally, the remarkable number of upset victories in the first round being a feature of the World Grand Prix owes itself to the chaotic best-of-three sets format.
Phil Taylor, eliminated four times by unseeded opponents in his first matches in Dublin, was dumped out of tournaments more often here than in any other round of any other televised tournament.
Consider also that Michael van Gerwen, in his 2017 first round loss, won more legs than John Henderson, and that world number two Rob Cross has never won a set in Dublin in his two previous appearances.
A virtuoso display of doubles accuracy can end a first round match in ten minutes, while a more scattershot affair can result in the match turning on tense and dramatic deciding legs. All of which occurs in an uncomfortable time frame - too short for the top players to settle into their rhythm, but just long enough for underdogs to make their mark.
Unlike other tournaments whose titles reward feats of endurance over long matches (World Matchplay), or long tournaments (Premier League), in which a dropped leg or match is no great setback, the World Grand Prix offers no consistent rewards to players with small long-term statistical advantages over others.
The man of the moment - who can double-in with the first dart in a deciding leg, or hit a crucial checkout to snatch a set from within his opponent's grasp - has the advantage in this chaotic and unpredictable tournament, even if his averages or doubles percentages would not otherwise impress.
The probability of upsets, the endless double attempts and the lingering possibility of a nine-darter make this tournament perhaps the most exciting one on the PDC calendar.