In his latest column, PDC Stats Analyst Christopher Kempf analyses the impact of a 170 checkout on the outcome of matches and how it influences player performance.
If the 170 finish has earned the nickname "the big fish", it has done so by not being particularly bigger than some of the other fish on offer.
170 is not the most difficult or the rarest checkout in darts; indeed, if prizes were still awarded - as they were 20 years ago - to the player recording the highest checkout of a tournament, the prize would need to be split several ways amongst the several 170-hitters of every tournament in the present day.
However, there is no denying the great psychological impact of a 170 checkout in a match, especially if a player's opponent was expecting to have the opportunity to return to the board.
As recently as this past Sunday, Nathan Aspinall's 170 finish was the decisive factor in his semi-final win over Gary Anderson, and this may have spurred him on to gain victory in the final by an 8-4 margin.
There can be, as yet, no quantifying how a player feels after a 170 checkout, but 12 years' worth of European Tour matches can tell us what improvement (if any) the players demonstrate in their performances.
Aspinall's was the 135th 170 finish known to have been completed in the history of the European Tour. Of those 135 'big fish', 91 were reeled in by the player who won the match on, or after, that checkout.
That throwing 170s and winning matches would be correlated is no surprise - one would expect that the players most able to complete high finishes would also be the players most likely to win legs overall.
The subject of our inquiry here is whether 170 finishes turn the tide of the match, causing those players who complete them to enjoy enhanced performance for the rest of the match, or to cause their opponents' form to decline, or both.
More than 17,000 darts have been thrown in European Tour matches containing 170 finishes, allowing us to get a picture of the effect of these outshots on the theoretical 'average player' in action on stage, if not for an individual.
That picture is not surprising insofar as it conforms to our intuition: that 170 checkouts encourage the players who hit them, and demoralise the players against whom they are hit.
Before a 170, the European Tour player averages 94.52 and his opponent averages 95.26 - he is 0.74 points behind. But after the checkout, the crowd, the momentum and the statistical advantage has shifted.
Suddenly the opponent (against whom the 170 is hit) is 0.95 points behind the player in averages; the only discernible cause for the 1.34 point drop in his averages is the shock he has felt at seeing his rival take out a score completed only 3% of the time in the PDC.
The effect is also noticeable in the percentage of legs won by both players before and after the 170; while the 170 hitter wins only 48% of his legs before the 170, he wins 52% afterwards (not including the leg won with the checkout).
The finishes can occur in the first leg, last leg, or somewhere in between; they can be as decisive as Aspinall's, or add a flourish to a whitewash; but in aggregate, a player with a 170 finish can expect to score more points and win more legs afterwards for no clear reason other than the effect of that finish.
Yet as we have said, 170 is no less common or more difficult than other high finishes, such as 161, 164 or 167.
In order to demonstrate that 170 really has a special impact in darts, we would need to show that the positive effect of completing a 170 checkout is bigger than that of these other checkouts of comparable rarity and difficulty.
To some extent, we can do that: a player throwing a 161, 164 or 167 wins more legs than before by a slightly smaller margin of improvement relative to a player throwing 170, but does not win a majority after the checkout (49.9%).
In terms of changes to averages, however, the difference is most noticeable. Completing these other three high checkouts increases a player's average by an amount four times smaller and decreases their opponent's by an amount six times smaller than completing 170.
Even if 167 is more difficult and more rare, the fact that it is a smaller number apparently makes all the difference when it comes to in-game psychology for the players involved.
In the 2025 Premier League, the players have left the 170 finish 55 times in the first seven weeks, leading to more than one attempt per match. The only finishable scores left more often are 40 and 20.
Never before have players chased after 'the big fish' so frequently or with so much success, and the knowledge that landing one actually gives an advantage in the match beyond the single leg won will surely encourage every darts player to bait their hooks.
Follow Christopher on Twitter @ochepedia