Wednesday, November 25, 2009

Split Personality Disorder

Lately, I have been plagued by splits, and so have two of my compadres (JD and JL). This week our team put up 18 of those pesky buggers. We have had more than 10 for seven of the last eight weeks and have maxed out at 20. Splits are huge nuisance, especially pocket splits. They are keeping our pickup percentage down. For instance, this week, I picked up 9 of 17 spares or 52.9%. Of the eight that I did not collect, 6 were splits. So, of the "normal" leaves, I had, I actually got nearly 82%. If I could largely eliminate splits, then, I could probably add at least 10 pins to my average. This goes for most bowlers.

Well, in this post, I would like to make the argument that splits are a sign of improvement in bowling; I'd actually like to turn this rise in splits into a good thing. It's rare in sports that a gain in skill comes with an unfortunate side effect, but I'm pretty sure that's exactly what's going on here.

I'd like to start with a simple conceptualization of skill in shooting a basketball. The same idea could be applied to darts or any activity where something is propelled toward a target. In basketball, the target is the center of the rim. If a shooter shoots 1,000 free throws, they will make some and they will miss some, but if we were to look at the average location at which the ball would have passed through the plane of the rim, it will usually be the center of the rim. Parenthetically, did you know that the diameter of the rim is twice the diameter of the ball?

For a really poor shooter, Shaq for instance, that scatter of dots representing each shot will be wide. Some will be air balls. Some will be swishes. Some will clank off the rim to the right or left. Some will brick off the back of the rim or backboard. For a really good shooter, like Steve Nash, that scatter of points will be much tighter. Most will be near the center of the rim, and the misses will be near misses. The scatter of points made by both shooters should be centered on the center of the rim. For a good shooter, though, the dispersion, or the width of that scatter, will be much tighter.

Now let's apply the same concept to bowling. On the first ball, we all aim for the pocket, the 1-3 if you are a righty. Some of us are better at consistently finding it than others. For a really low skill bowler, if we could average all of the locations of contact of the pins (say the board of entry), it would be the pocket. In fact, this would be the most likely shot, but a large number of shots would miss, and many would miss badly, with some even finding the gutters. Below is a graphical representation of the system as I envision it. (Click on it to make it larger).
The beige curves above the pins represent the frequency distribution of 1st shot locations for low, intermediate, and high skill players. If I had actual data for this, I would expect the distribution to be normal, bell-shaped, or Gaussian, named after Karl Friedrich Gauss (the old guy in the pic up there). Incidentally, if you are interested in tracking board (or location) statistics, check out Bowl SK, a bowling stats package maintained by our friends at the 10th Board. In brief, the height of the curve represents how commonly a shot reaches the pins at a particular location. The most common location is the pocket for bowlers of any skill, but as we improve, those shots on the edges of the pins become increasingly rare until they largely disappear. Professional bowlers are almost always very close to the pocket.

Here is the interesting part. As your skill increases from low to intermediate, you should find the pocket and its surroundings more frequently. Because most splits derive from striking the 1 pin straight on (very close to the pocket) , splits should actually increase in frequency as you improve. If you can get beyond this stage to the high skill level, they should drop off again.

I don't have board statistics for our team to demonstrate this phenomenon. As quantitatively anal as I am, I just can't bring myself to record this information while bowling, but I do have one way of looking at the problem: 1st ball average. If you have a high 1st ball average, it means that you are regularly near the pocket on your 1st toss. If it is low, you are all over the place. It should be a good proxy for skill. So, we can ask whether the number of splits increases as first ball average increases?

Above is a graph of 1st ball average vs. the number of splits for 93 individual series of bowling for bowlers of low to intermediate skill.Notice that above a 1st ball average of 7.5, the average number of splits per series increases by one for every 0.5 pins gained in 1st ball average.

What does this mean? It means that if you are getting more splits and you are improving from low to intermediate skill, this is exactly what should be happening, as annoying as it may be. It is a sign of improvement. So, try not to think of it as a bad thing, as I have been. It is my contention, although I do not have the data to back it up, that as you improve even further, the number of splits you get will decline again. Here's one little bit of evidence to support that idea. Two weeks ago, JD put up a first ball average of 9.03. It was the first time any of us had broken the 9.0 mark. How many splits did he have that night? Only one.


  1. I'm glad to see your post. I've had the same thoughts, the more I'm around the head pin on 1st ball, the more splits I get. And that ofter turns a 2 open game into a 4 open game.

  2. Hey Doc, It's always nice to hear that someone agrees. -Todd


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