Master of Science / Department of Statistics / Abigail Jager / Baseball has long provided statisticians a playground for analysis. In this report we discuss the history of Major League Baseball (MLB) umpires, MLB data collection, and the use of technology in sports officiating. We use PITCHf/x data to answer 3 questions. 1) Has the proportion of incorrect calls made by a major league umpire decreased over time? 2) Does the proportion of incorrect calls differ for umpires hired prior to the implementation of technology in evaluating umpire performance from those hired after? 3) Does the rate of change in the proportion of incorrect calls differ for umpires hired prior to the implementation of technology in evaluating umpire performance from those hired after? PITCHf/x is a publicly available database which gathers characteristics for every pitch thrown in one of the 30 MLB parks. In 2002, MLB began to use camera technology in umpire evaluations; prior to 2007, the data were not publicly available. Data were collected at the pitch level and the proportion of incorrect calls was calculated for each umpire for the first third, second third, and last third of each of the seasons for 2008-2011. We collected data from retrosheet.org, which provides game summary information. We also determined the year of each umpire’s MLB debut to differentiate pre- and post-technology hired umpires for our analysis. We answered our questions of interest using longitudinal data analysis, using a random coefficients model. We investigated the choice of covariance structure for our random coefficients model using Akaike’s Information Criterion and the Bayesian Information Criterion. Further, we compared our random coefficients model to a fixed slopes model and a general linear model.

The information presented herein attempts to quantify the conditions surrounding concussive impacts from foul tips to the masks of catchers and umpires in baseball. Media reports of such occasions were researched on video and pitch speed data from the Pitch F/X system recorded to suggest speeds and locations at which impacts occur. To evaluate mask performance, a pneumatic-wheel, electric-motor driven pitching machine was utilized to shoot baseballs at the instrumented head of a Hybrid III dummy. Head accelerations were calculated from a 3-2-2-2 accelerometer array to allow for comparisons of linear and angular kinematics. 6 common masks (2-piece traditional-style and 1-piece hockey-style) were tested at 7 locations at 60 mph to determine the severity of each location. The center-eyebrow and chin locations were further tested at 84 mph. Speed and location data were used to evaluate a large sample of 25 masks to explore possible performance differences between manufacturer models, mask types and cage styles. The results of this study showed no significant difference between hockey-style and traditional-style mask performance. Titanium caged masks, although lighter than their steel counterparts, experienced higher linear accelerations. However, all masks experienced linear and angular accelerations well below commonly accepted injury thresholds. Yet, concussive injury has still occurred in the players and umpires that wear these masks. The work presented here can be used to help better understand these thresholds and influence the design, construction and evaluation of a new generation of masks that decrease the risk of concussions to the wearer. / Master of Science

Cricket umpiring is demanding. In today’s world where so much technology is available to television viewers, they expect perfect umpiring, forgetting that what they see on their television screens is not available to the umpires standing in the middle of the field making the decisions. This study aimed to examine cricket umpires on-field decisions during the 2007 ICC Cricket World Cup. Examining leg before wicket (LBW) and caught behind decisions, in particular. The researcher made use of a notational analysis program known as Umpirestat to collect the necessary data on each umpire. The umpires were examined in two groups Elite and International umpires (groupings defined by the ICC) and were compared to a base line in the form of Hawk-Eye for LBW decisions and TV replays for caught behind decisions. The umpire groups were compared to each other and then to the base line, an individual umpire comparison was then done within each grouping. The data was statistically analysed using percentages, chi squared and modelling for the Elite Umpires. For LBW decisions there was a difference of 2.02% between Elite and International umpires, showing a similarity between the two groups. The difference between Elite Umpires and Hawk-Eye was 18.83% and between International umpires and Hawk-Eye was 16.81%, showing difference between the three groups. It was found that there was a difference of 3.63% for caught behind decisions between Elite and International umpires, showing a similarity between the two groups. The difference between Elite Umpires and TV replays was 2.99% and between International umpires and TV replays there was 0.64%, showing similarities between the three groups. In conclusion, for LBW appeals there is a similarity between Elite and International umpire groupings however a difference exists between Hawk-Eye and both groupings of umpires. For the individual umpires LBW comparison the following was seen for the International umpires; no real conclusions could be drawn due to limited amounts of data collected on them. However, variances in individual performances were seen within the International umpire grouping. For Elite Umpires, it is clearly seen in the model that the umpires expected number of dismissals got closer together and almost group together at around four appeals. This indicates a strong consensus amongst umpires when dealing with four, five and six appeals during a match. This consensus is more pronounced for four and five appeals. In conclusion, for caught behind appeals there is a similarity between Elite and International umpires as well as a similarity between replays and both groups of umpires. For the individual umpires caught behind comparison the following was seen for the International umpires; as with the LBW results there was limited amount of data available for the caught behind results. Thus no real conclusions could be drawn for International umpire caught behind decisions, although when examining the percentage data, differences can be seen. For the individual umpires caught behind comparison the following was seen for the Elite Umpires, no consensus is seen between the umpires - they all appear to have different expected dismissals to one another. Copyright / Dissertation (MA)--University of Pretoria, 2010. / Biokinetics, Sport and Leisure Sciences / unrestricted