“Jack high!” It’s a term we hear all the time around the green when a bowl finishes more or less inline with the jack. But how many of us actually know what it really means and why it matters?
Below is an image of two bowls and a jack, with a mat shown at the other end of the green, not to scale, to help me illustrate the direction of play. Which of the two bowls, A or B, would you say is “Jack high”?
A common misunderstanding is that a bowl is considered jack high (or jack level, as it’s sometimes called) when the centre point of the bowl finishes in line with the centre point of the jack (like bowl ‘A‘ in the above illustration). This thinking might sound logical, but according to the official Laws of the Sport (4th Edition, Law C.27.1), this is incorrect.
Here’s the official definition:
“Jack high (or jack level): A bowl is jack high if the nearest part of it is in line with and at the same distance from the mat line as the nearest part of the jack.”
In other words, we’re talking front edge to front edge as measured against the mat line [an imagined line that runs the width of the rink passing along the front edge of the mat] —not centre to centre. So if your bowl’s front is in line with the front of the jack, then yes, it’s jack high. But if the centre of the bowl lines up with the jack’s centre, your bowl is actually sitting in front of the jack. In fact, for a size 3 bowl that measures ~5 inches in diameter, it would be about 1.5 inches short of jack high.
It’s a subtle difference, but can be an important one—especially when it comes to choosing the right shot to play when a is bowl resting close to the jack. The below diagram shows what a difference accurate (or inaccurate) communication could make to a player’s shot choice and outcome.
Imagine you’re on the blue team, trying to take shot away from the red team who are holding shot with a touching bowl. The bowl in the left image, resting 1.5 inches short of jack high, is much more likely to be stuck first by a weighted draw shot delivered on the backhand, whereas playing the same shot towards a jack high bowl has a much better chance of removing the shot bowl without moving the jack, or taking the jack clean away from the shot bowl.
So next time before you call back “You’re jack high!” it might be worth a second look!
‘Umpire’s Corner’ is an irregular series of posts intended to demystify and clarify the laws and etiquette points of the sport of bowls. Written by the club’s in-house umpire, Alfie Simmons.
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