Monday, October 26, 2009

Lane Effects

As I have progressed as a bowler, I feel like I have become of more aware of the subtleties of the game. For example, like most of you, I know probably 90% of the time whether a spare will be picked up well before the ball reaches the pins, even for tricky spares. One of the things that I feel I am increasingly in tune to are lane conditions. Before I adopted the hook, this was largely irrelevant, but now that I have not only started chucking the ball with spin but with variations on spin, speed, and starting position, I feel like I can better pick up on subtle or sometimes not so subtle differences between lanes. I suspect that most good bowlers do this and even some bad ones, like myself.

Over the last several weeks, for the first time, I have been trying to adjust my throw depending upon the lane on which I am bowling. This has been a big realization for me, but I'm not sure it has really helped my game that much. Anyway, it got me thinking about lane effects. There are nights when it seems like most of your strikes come from one particular lane, whether the right or the left. Last week, the right lane seemed very ornery, like it had been coated with Arrid Extra Dry.

So, I thought I would check the BM database to see whether clear lane effects were present. I thought they would be. I expected that there would be many nights when the great majority of strikes came from a single lane. I also expected to see that for those of us who bowl with spin, there would be a greater bias toward a single lane than for straight ball throwers. It turns out that neither prediction is true.

Ok... this one is going to be a little dense from here on out. This is where everybody usually changes the channel. Bye bye.

Still here? You are a dork. For each bowler and night of bowling, I counted the total number of strikes that were garnered on the home and away lanes. If you start with the null assumption that a strike is equally likely for both lanes, then it is possible to compare actual outcomes to predicted outcomes. We have definitely had some biased nights, such as nights when all of a bowler's strikes came from a single lane. This has happened four times. However, it has never happened if a bowler has recorded more than four strikes. In other words, when it has happened, it has not been unusual. Think of it this way. If you are tossing a coin, you might get all heads or all tails, but this would only be an unusual result (less than 5% chance) if you made a lot of coin tosses, more than four to be exact. If you only made two coin tosses, you wouldn't be surprised if they were all heads. Likewise, if you only got two strikes, you wouldn't be surprised if they came from the same lane. If you got 10 strikes all from the right lane, yeah, that would be weird, but it apparently very rarely happens.

Ok, so for each series, I checked which lanes had the most strikes. Occasionally, both lanes had the same number. The lane with the most, I called "max" and the lane with the fewest "min". I then summed the total number of strikes for the max and min lanes by bowler. This allowed me to check how biased each of our strike numbers are to a particular lane. What I found, as shown below, is that on average, all five of the Movements record about 60% of our strikes from a single lane. The slight differences are not meaningful.

Well, 60% seems like there might be a meaningful bias here, but there isn't. I don't really want to explain why, but this is exactly what you would expect if there were no lane effects, meaning that a strike is equally likely in both lanes. The way the analysis is designed insures that these numbers will deviate from 50%, but the observed deviations are not large enough to be considered meaningful. I'll leave it at that. If I group the straight and hook bowlers, again no difference is evident.

What does this mean? Well, perceptions can be deceiving. My gut told me that clear lane effects should be present, but the reality is that they aren't. Unusual nights will happen, nights when it seems like you struggle to get a strike on the left side. But unless it is happening to you all the time, it can just be chalked up to chance.

7 comments:

  1. If Geoff and I had a higher number of strikes it might also be a good measure - especially given our skill. I would think lane conditions would have less impact on a straight bowler??

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  2. I'm not a scientist but it would seem to me that lane conditions could also impact a straight bowler. Assuming a straight bowler always hits the pocket (which I never accomplished), it would seem like oily lanes would cause a ball to slide down the lanes and deflect away from the 5 pin when hitting the pocket while dryer lanes would allow a ball to come out of its initial slide down the lane and roll thru the pocket driving thru the 5 pin. The bigger problem is bowlers like us don't hit the pocket often enough to test the theory.
    You are right about one thing though. There aren't many who will appreciate this discussion.
    The HCLC doctor

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  3. Well, Rook, I thought so, too, but the data do not seem to bear that out.

    Doc, good thought, indeed. Do you leave a lot of five pins? I suppose this could be chalked up to the skid or lack thereof from oily/dry lanes. I guess the way I saw it was that if you are a true straight on bowler, the ball will take the same trajectory no matter what's going on with the lanes. But I like the idea that it might maintain more velocity if the the lanes are oily. Is that the opposite of what you just said.

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  4. You know, you'll get more out of the team doctor if you by him a pitcher of beer.

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  5. If the team doctor is a fan of bowling juice, he should read this:
    http://bowlmovementswy.blogspot.com/2009/06/on-beer-and-bowling.html

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  6. The team doctor and I have talked about this... We have discovered that there is a "beer window" when we bowl. We know we're through it when our game and scores go south (see fifth game commentary at http://thumbhole.blogspot.com/2009/10/should-have-stayed-off-knee.html); however, I (like you mentioned in your post) see little correlation between amount of beer and amount of pins. I have bowled poorly sober as a judge and I've bowled well loose as a goose... Just another aspect of this universe that is a mystery to me.

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