Sunday, July 26, 2009

Help Wanted

Over the three year history of the Bowl Movements, there has been a three man core... Johnebob, JD, and myself. The fourth spot has been occupied by an amazing array folks. Even if you put them in a clown car, you would be impressed at how many idiots would come out. First there was Z. Then, Jimmy Jazz. Becker and Timmy filled the role, as did Woody. J-Shane has filled in, as has the Gingasaurus Rex. But for all but a couple of weeks of last season, the spot was occupied by El Jefe, the man with free health care when he goes home to the Great White North.

El Jefe, the straight on bowler, has decided to move on to greener pastures. Ironically, he is heading to Reno, the home of the National Bowling Stadium. We expect to watch him bowling there soon... when his average finally crests 130. The Canadian will be sorely missed for his steady demeanor, his quiet head shaking after chucking one in the gutter, and his 9 open-frame games. He served two purposes on our team. He was a cool, collected, and easy-going presence. Also, he made the rest of us feel good about our bowling skills. He is, after all, the founding member of the 88 club. Check the records on the right if you don't know what that means. He will be missed.

While a loss of a team member provides an obvious venue for mourning, we see it more as an opportunity for celebration. Here is a toast to all of the men who have been so proud to have called themselves a Bowl Movement.

Now to the point of this post. Do YOU want to be a Bowl Movement? This may be a once in a lifetime opportunity to wear the red and black. Requirements: 1) You must live within a 100 mile radius of Laramie, Wyoming. 2) You must have a sub-140 average, but 120-130 is preferable. 3) You must be willing to pay $12 to get your ass kicked at bowling every Monday night at 8:30 from September to May. 4) You must enjoy the imbibing of the bowling juice. That's it. If you think you have the right stuff, let us know.

Friday, July 24, 2009

A hot hand effect in bowling?

This post was inspired by something I read on the blog The Hot Hand in Sports, which is maintained by Dr. Alan Reifman of Texas Tech University. The basic idea of having a “hot hand” is that athletes are commonly perceived to be streaky. They go through phases during which their batting average or field goal percentage is very high followed by periods when it is very low. Of course, even if skill remains absolutely constant, such streaks, good or bad, can occur by chance. So, are these hot streaks and slumps real, or are they the product of the inevitable role of chance? If you are interested, you should check out his blog. It’s very interesting.

With respect to bowling, this made me ponder the following question. Do prior outcomes affect future outcomes? Specifically, I was wondering if bowling a strike makes us more likely to bowl a strike on the next frame. There is reason to believe it might. I am constantly adjusting my throw and approach depending upon prior outcomes. Generally speaking, if I get a strike, on the next frame, I will try to replicate exactly what I just did. Also, the muscle memory of the prior throw should be fresh. So, it might be expected that a strike is more likely to follow a strike than a prior non-strike first ball. That said, if I don’t get a strike, I adjust my next throw accordingly to try to get one. I assume we all do this to some extent. So, maybe it all balances out. Maybe a strike is equally likely to follow a strike as opposed to any other first ball.

Before you get into the analysis below, I should forewarn you that it’s a little dense. Sorry.

To answer this question, I looked at all 252 games in our database, specifically the first ball outcomes for paired frames (n=2436). For a given bowler, I looked only at frames in which a strike was recorded, and I determined the number of strikes that follow strikes versus the number of strikes that follow non-strike first balls. It should be no surprise that strikes far more commonly follow non-strikes. In our database, we have 456 strikes that follow non-strikes, and only 150 strikes that follow strikes. This alone does not answer the question because we only strike about one out of four of frames as a team, and therefore, we have a lot more opportunities to follow a non-strike with a strike. The question is whether a strike makes the next frame more or less likely to be a strike. In short, when we roll a strike, in 24.8% of cases, we follow this with a strike. When we don’t roll a strike on the first ball, we receive strikes on 24.9% of frames. Strikes appear to be equally common no matter what happened in the prior frame.

To explore this a bit further, I decided to examine the average first ball score on subsequent frames given the outcome of the first ball on the prior frame. Again, there is no evidence for hot hand effects. We average between 7.5 and 8.5 pins on the first ball no matter what happened in the prior frame. If anything, there might be a weak “reverse” hot hand effect, meaning that we do slightly better if we bowl poorly in the prior frame.

What does this mean? It means that we likely do not go through hot and cold phases in bowling in a given night. I’m guessing that your intuition probably disagrees with this, but intuitions are not always good judges of reality. It is very easy to see a “cold streak” if simply by chance you have many unlucky outcomes in a row. Likewise, getting a turkey may seem like you are really “feeling it”, when in fact it should happen from time to time simply due to chance. When you look only at strikes, there is basically no evidence of “hot hands,” that getting a strike does not make a strike on the next frame more likely.

Think of it like rolling dice. There is 1/6 chance that you will roll a one on any given throw. So, occasionally, you will roll five one’s in a row (On average, you’ll have to roll the dice almost 8,000 times for this to happen) This did not happen because you were on a “hot streak,” or because you were very skilled at rolling dice for five throws. It happened because of luck. Now simply substitute bowling strikes in the above analogy. Differences in skill will cause some bowlers to roll more strikes than others which in effect changes the basic probability of a strike, but over a given night of bowling, it really looks like those probabilities don’t change much.

It would be interesting to do this analysis for individual bowlers rather than for the team as a whole, but as always it would require a lot more data. My hunch is that hot and cold streaks may affect some bowlers more than others.