Results from a Study on Specifications presented to World Bowling Executive Board


    World Bowling News

    Republished courtesy of World Bowling Newsletter (2014-04-05)

    2014WorldBowlingLogo.jpg World Bowling, formerly the World Tenpin Bowling Association (WTBA), has partnered with the United States Bowling Congress (USBC) and the Hong Kong Sports Institute (HKSI) to conduct a study on bowling specifications for elite level competition.

    Specifically, the goal of the study was to create a distinguishable platform for elite world competition with scoring being the key measurable. During the development phase of the study, bowling was broken down to the following components: lane conditioner, pins, lane patterns and balls.

    Lane conditioner is always evolving and Kegel is the lane maintenance partner for World Bowling. As such, it was decided that the new Kegel lane conditioner, Ice, would be used during the test.

    According to the manufacturer's website, "Ice is designed to be pinsetter and house ball friendly while also delivering a high level of durability."

    Due to these properties it made sense to try out this lane conditioner since it is desirable for the playing conditions to hold up and have the lane conditioner be friendly to the environment during testing.

    Data on heavier and lower center of gravity bowling pins were examined. The data showed that pins with lower center of gravities would not create a desired affect on scoring within the level of bowlers being considered in this study.

    Heavier bowling pins were also considered, but after looking through the previous test results, heavier pins had an adverse effect on the pin setting machinery and are very difficult to manufacturer.

    After looking into these aspects, it was decided that the logistics of having special competition sets of pins that are within different specifications ranges from standard pins would be far too complicated from both the manufacturing front, equal opportunity for each country to have them to practice on as well as shipping and installing at all competition sites.

    World Bowling has a set of lane patterns that are sport bowling compliant. There are four short patterns, four medium patterns and four long patterns. Each country is familiar with this set of lane patterns.

    A new lane conditioner is being used in the study so lane patterns were chosen from the current banks of patterns to gain insight on how the conditioner would work within the already existing patterns.

    This left the specifications on bowling balls as something that could be further investigated. The question was presented – If the specifications on bowling balls are limited would a significant difference in scoring be seen?

    Once the main question to be answered was developed a test method was chosen utilizing Six Sigma strategies.

    USBC would have 12 different bowlers bowl 6 games on 2 different WTBA lane patterns twice using any USBC approved bowling ball they wished. These same 12 bowlers would then bowl using only bowling balls that fall within tightened specifications – 6 games on 2 different WTBA lane patterns twice.

    For every session of bowling, each bowler would record their game scores, the ball they were using, if they made a ball change – which frame the change was made in and the surface grit of their bowling ball, etc.

    Lane tapes were also taken and used to verify that the lane patterns were the same for each test session on the particular pattern. This same process was to be done by bowlers at the HKSI so a replication of the test could be conducted.

    Researchers turned to the USBC Ball Motion Study to determine which bowling ball specifications to focus on for the study.

    The USBC Ball Motion Study produced results that showed Surface Roughness measurement of Ra, Low Radius of Gyration, Total Differential and Intermediate Differential were all top influential factors on ball motion that can be measured on a ball.

    Specifications on these factors were to be limited in the study. Data from the last 10 years of approved bowling balls was examined. Specifications were pushed as tight as possible for the study. Once results were available, if shown applicable, a specification could be loosened.

    Table 1 shows the current USBC bowling ball specifications and the limited specifications for the study. The limited specifications only apply to the bowling balls used in the limited equipment sessions.

    The limited specifications were selected by examining a distribution analysis on each specification from bowling balls over the last 10 years. The distribution analysis along with the associated probability plots allowed researchers to understand what percentage of bowling balls would be eliminated based on where the limited specifications were set.

    Table 2 shows the percentage of the population of bowling balls that are eliminated based on each individual specification on its own with the specification being set at that level.

    Once the bowling sessions were complete, all of the data is entered and the differences between scores from the sessions using any USBC approved bowling ball the bowler wished were compared to the scores from the sessions where bowlers only used bowling balls that fall within the limited specifications.

    Running the data through a two-sample test showed that the greatest observed statistical difference between the two sets of scores was 7.18 pins per game.

    At this point USBC representatives discussed with the World Bowling Executive Board the difference between statistically significant differences and practically significant differences.

    The test showed that statistically there is a significant difference between the scores with any bowling ball and the scores with only balls from within the limited specifications. It is very important to consider how that difference fits into the bowling environment and decide if it is practically significant within this situation.

    To go down the path of allowing only a limited list of bowling balls at world competition for a minimal difference in scoring (less than one full mark per game) would mean putting in substantial time and effort for very little return.

    The Board discussed recommendations presented based on the difference in scoring produced.

    First, the specifications had been tightened on the balls to the point where there were not many left within that range for use. Specifications could be narrowed further, but that would even more drastically limit options available on the market for use. It was decided that something other than bowling balls would have to be examined.

    The next recommendation proposed was to see what could be done to the lane patterns. The ratio of the current banks of WTBA lane patterns have not changed significantly in several years. A very rough analysis on scoring data from the 2013 PBA World Series of Bowling events and the 2013 Bowling's U.S. Open was conducted.

    The PBA World Series of Bowling is conducted on oil patterns that have ratios around 3:1 (the same ratio as World Bowling lane patterns). Bowling's U.S. Open was conducted on a 1:1 ratio oil pattern. Analysis showed that bowlers who bowled both the 2013 PBA World Series of Bowling and the 2013 Bowling's U.S. Open averaged 14 to 30 pins higher on the PBA World Series of Bowling oil patterns.

    To examine this even further the 2013 USBC Queens and 2013 Bowling's U.S. Women's Open were considered.

    The 2013 USBC Queens was conducted on an oil pattern that had a 3:1 ratio and the 2013 Bowling's U.S. Women's Open used an oil pattern that had a 1.5:1 ratio. Within these two events, bowlers who bowled both events averaged 14-pins higher at the 2013 Queens which trends similarly to the difference seen with the PBA bowlers.

    The World Bowling Executive Board has decided to try out some lower ratio lane patterns at a few 2015 World Bowling events. A few of the WTBA patterns will be adjusted for the start of 2015. The ratios of these lane patterns will range between 2:1 and 2.5:1.

    This avenue allows World Bowling to create a playing environment that can be practiced on outside of the competition sites. The elite bowlers of the world will continue to be challenged and rise to meet that challenge.

    To review the full Study on Specifications for Elite Level Competition, click here.