It's not the 7-10 Split
February 18, 2015 9:25 PM   Subscribe

 
Something's wrong with this analysis. The 4-6-7-9-10 "Greek Church" has a 0.3% spare rate while the 4-6-7-8-10 "Greek Church" has a 1.3% - averaged they are a 0.8% spare rate, higher than the 7-10 split of 0.7% which should by equivalent to the symmetrical 10-7 split.

The article mentions this is possibly due to handedness but than fails to go back and correlate the frame vs the handedness of the bowler. The real percentage then for making a lefty Greek Church should be *lower* if you're a right hand player and vice versa for the righty Greek Church. The likelihood of making a 4-6-7-9-10 is dominated by what hand you are - it's not the hardest split in the game if you are left handed for instance. The 4-6-7 vs 4-6-10 split has a similar deal but overall is harder than the 7-10.
posted by pmg at 10:24 PM on February 18, 2015 [4 favorites]


This has everythibg Ilike in it. Bowlung, numbet crunching and the movir Kingpin. Sorry for all the typos, it is hard to type on a smartphone with a rubber hand.
posted by Literaryhero at 10:25 PM on February 18, 2015 [15 favorites]


More seriously, pmg, that is a great analysis. It doesn't really effect my interest in the article, but it does remind me to be careful with my numbers!

Also it seems like the mirrored 4-6-10 and 4-6-7 end up at only .65% total, so the 7-10 split is still not the most difficult split. That doesn't take handedness into account, but I still think it is interesting.
posted by Literaryhero at 10:33 PM on February 18, 2015


I'm annoyed by all the numbers with only one significant figure.
posted by Phssthpok at 10:57 PM on February 18, 2015 [1 favorite]


The article takes a weighted average: one Greek Church appeared 785 times and was converted 2 times, and the other appeared 149 times and was converted 2 times.

(2+2)/(785+149) = 0.0043 = 0.43%
posted by Pyry at 10:59 PM on February 18, 2015 [8 favorites]


I wonder if there's a possibility on spares with 3+ pins that bowlers will often play a bit "safer" to one side, to ensure at least the majority of the pins, while possibly sacrificing a loner off to one side, hence the disparity. Whereas with a 7-10, there's less reason not to simply "go for it," knowing you're just about guaranteed to hit at least one.
posted by ShutterBun at 11:06 PM on February 18, 2015


Pyry that's a great point. With only two conversions for both sets that's a huge amount of variability and hardly settles the matter. This dataset only goes back to 2003. We have to go deeper.
posted by pmg at 11:11 PM on February 18, 2015 [1 favorite]


The thing I found interesting was that there's a huge disparity in the appearance of mirror-image splits. If you look at the 4-6-7 and 4-6-10 for instance, the former appeared 1818 times, and the latter only 775.
posted by Joe in Australia at 11:30 PM on February 18, 2015


Surely that's due to the handed-ness of the original roll?
posted by ShutterBun at 12:00 AM on February 19, 2015


Yes, probably. I'm just surprised it was such a strong effect.
posted by Joe in Australia at 12:24 AM on February 19, 2015


Which is maybe a more interesting story in that it seems like the leftys then do better at converting the more difficult spares.
posted by Literaryhero at 12:36 AM on February 19, 2015 [1 favorite]


That's a bit of a leap, as we have no idea if those who were *successful* in converting either were right or left handed. It could very well be that 4-6-7 was an uncommon spare for a righty to be faced with, while they nevertheless had an easier time converting it. #notrighty-ist
posted by ShutterBun at 3:47 AM on February 19, 2015 [2 favorites]


I'm annoyed by all the numbers with only one significant figure.

Math is the most difficult split.
posted by Dip Flash at 4:20 AM on February 19, 2015 [3 favorites]


OK, I think I might have to go bowling this weekend to add a few data points. Of course, I'm a pretty casual bowler and so a common outcome of a 7-10 split for me is a gutter ball. I'll go review this AskMe for pointers.
posted by TedW at 4:34 AM on February 19, 2015 [2 favorites]


I'm ok with only only one significant digit, but I'd like to be convinced that there's at least one. Inferring "0.3% chance to convert the 4-6-7-9-10" from 2 samples out of 785 seems optimistic.

It'd also be nifty to re-run this analysis on right-handed bowlers only. You only throw out ~10% of your data and immediately remove the biggest source of bias.
posted by Nelson at 5:28 AM on February 19, 2015


Surely that's due to the handed-ness of the original roll?

Yes. The ideal shot curves into "the pocket", the space between the 1-2 or 1-3 pins, depending on if you're right or left handed and where you set up. The conventional curl has you setting up to the right and hooking the ball to the left into the 1-3 pocket if you're right handed.
posted by eriko at 5:59 AM on February 19, 2015 [1 favorite]


I wonder if one's belief in which shots are more difficult has a significant effect on which one makes. Once the 4 minute mile was broken, others were able to do it. Knowledge of these statistics should change future statistics.
posted by Obscure Reference at 6:52 AM on February 19, 2015


Of course, I'm a pretty casual bowler and so a common outcome of a 7-10 split for me is a gutter ball.

Surely the most common outcome is actually a field goal?
posted by Jpfed at 6:55 AM on February 19, 2015 [1 favorite]


Yeah, I saw this headline and the first thing I thought was "Greek Church."

The better odds for lefties converting this spare is due to the fact that bowling is generally easier for lefties in general. Because there are vastly more right-handed bowlers, lane conditions (i.e. the pattern of the oil on the lane) break down much more quickly, leading to a less predictable ball reaction.

When a rightie is trying to hit the 6-10 just right on a Greek Church to kick the 6 pin across the pin deck, the unevenness of the lane conditioner in the path of the ball will make it harder to get the accuracy you need.

Conversely, when a leftie is trying to hit the 4-7 just right to kick the 4 pin across the deck, the lane oil won't be disturbed nearly as much, enabling the left-handed bowler to shoot much more accurately.

When you get to the upper levels of competitive bowling, you'll see proportionally many more left-handers than in general. This is because left-handed bowlers have easier conditions to bowl on throughout a tournament, as their lanes don't break down as quickly as they do with the greater number of right hand bowlers.
posted by slogger at 7:23 AM on February 19, 2015 [5 favorites]


Couldn't the 7-10 split appear statistically "easier" because people (professionals, mainly) practice it more than the other ones?
posted by demonic winged headgear at 7:28 AM on February 19, 2015


Regardless of the math, the thing that makes the 7-10 more difficult in my estimation as that you're relying on a 'lucky bounce' of the pin off the side wall or out of the pit. All of the other splits have a "shot" that will often allow you to make them.

I've picked every one of those damned splits except the 7-10 and the 2-8-10 ...
posted by Jacob G at 8:05 AM on February 19, 2015


My husband was FLABBERGASTED once when I got an 8-10 split (since we're both left-handed, it's sort of the equivalent of the 7-9 for a righty, I think?)

I forwarded him the article; it'll be interesting to see what he says.
posted by Lucinda at 8:11 AM on February 19, 2015


Which is maybe a more interesting story in that it seems like the leftys then do better at converting the more difficult spares.

I don't think that's quite the right conclusion to draw here. Unless I missed it, the numbers didn't spell out the handedness of the bowler. And while yes, you're going to get different frequencies of a 4-7-10 and 6-7-10 based on the handedness, either one can be left by a bowler using either hand. Without specific numbers, it's hard to know whether it's that a lefty does better with their more common leave, or the more uncommon one is somehow easier to pick up.

After all, as a right-handed bowler, I'm sure that there was a noticeable difference in picking up corner pins for me - I seem to recall that a 7-pin was pretty much a sure thing, but that standing left and shooting for the 10 was always a bit more of a challenge. I wouldn't be surprised to see I was also more likely to convert a 4-7-10 than a 6-7-10.
posted by evilangela at 9:06 AM on February 19, 2015


(This is what my husband said)

"Interesting. The 7-10 is easier because you only need to bounce one pin into the other. Believe it or not, there are some strategies for doing this, depending on the brand of pinsetter the hall uses."
posted by Lucinda at 9:11 AM on February 19, 2015


I used to league bowl back in the 70's, and I still bowl about one a year but it has been a few decades since I have broken 170.

Since I bowl with my right hand I primarily shoot straight or with a curve to the left, it is much harder to pick off the 10 than the 7 as I can't really use the whole lane to get at the pin on the right as it has the gutter to the right from my point of view.

I have used the gutter to get a 7-10 but I slam the ball into the gutter on the right just ahead of the pin and hope to clip it, or get a rebound out of the gutter, I am able to do this about 1 in 50.
More luck than skill.
posted by boilermonster at 9:40 AM on February 19, 2015


Here's a great video of PBA 7-10 pickups.

Here's one of Sean Rash converting a Greek Church.

And just for fun, here's one of Mike Machuga taking a header (which I came very close to doing in league last Monday night).
posted by slogger at 10:05 AM on February 19, 2015


>Of course, I'm a pretty casual bowler and so a common outcome of a 7-10 split for me is a gutter ball.
Surely the most common outcome is actually a field goal?


Usually you are trying (as a right hander) to hit the 7 pin on its left and most bowlers send the ball curving too far and into the left gutter.
posted by linux at 10:21 AM on February 19, 2015


Yes. The ideal shot curves into "the pocket", the space between the 1-2 or 1-3 pins, depending on if you're right or left handed...

Strangely enough, in my long-ago experience (and in my highest-point game) as a rightie, I had more strikes throwing Brooklyns. I 'spect it depends on the energy you impart to the ball. I also think I recall more nasty splits in the conventional pocket.
posted by Twang at 10:38 AM on February 19, 2015


This analysis is completely useless. It claims it is statistical data from professional bowlers. But it fails to account for two variables:

1. How often that split actually occurs in live play.
2. Skill of the bowler.

Maybe they could make some statistic on spare conversions as a percent of all rolls. But even then, the largest variable is the skill of the bowler. I remember my bowling coach used to drill us on specific splits, they can all be converted, but your percentage depends on whether you know how it can be converted, and your practice at converting that particular split. But overall, the surest way to convert strikes is to never have them in the first place. The toughest shot in bowling is the strike.

I had more strikes throwing Brooklyns. I 'spect it depends on the energy you impart to the ball. I also think I recall more nasty splits in the conventional pocket.

Brooklyns cause more spares. If you recall more splits in the 1-3 pocket, you probably didn't have enough hook, or you were looking at the pins instead of your your marks.
posted by charlie don't surf at 11:29 AM on February 19, 2015


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