provides more opportunity for scrum packs to contest for the ball; knowing the force development characteristics of their scrum pack could help coaches make tactical, training, and player-selection decisions on the basis of empirical data and experimentation. Two recent systematic reviews both highlighted the lack of research about scrum performance and the need for more data about the forces generated in the scrum and the force-time curves associated with scrummaging, especially during the sustained push phase where players contest for the ball [2,3]. Currently, there are several tactical decisions made by coaches in the scrums, such as using tight or loose binds, whether to try to wheel (i.e., attempt to rotate the whole scrum), and how much the flankers or #8 player should push versus being loosely bound and ready to disengage to make the tackle or support the ball carrier; however, none of these tactical decisions is informed by data. The primary reason why these decisions have to be made in the absence of data is the lack of equipment available to measure scrum forces. In athletic fitness testing, coaches typically use free weights or force plates to assess the strength of their athletes. While force plates provide a high level of detail about the force-generating capabilities of athletes, and many are now portable, such as the Bertec Jump force plate (Bertec Corporation, Columbus, OH, USA), they are designed for testing the strength of a single athlete in a generally vertical position, which is not very specific to the scrum. Therefore, a device with similar capabilities to a force plate but that enables athletes to mimic the rugby scrum position is needed--hence, instrumented scrum machines. There are very few commercially available apparatuses that can measure the force generated in a scrum, and the only ones the authors are aware of are made by Predator and range from \(\epsilon\)4200 for an individual ergometer to \(\epsilon\)7100 for an indoor ergometer that can accommodate a whole pack to \(\epsilon\)12,200 for a fully instrumented scrum machine [8,9]. In the last 30 years, a few apparatuses have been built by researchers to measure scrum force for research purposes, though many of those have been limited to a single player at a time. In many of the research studies that did find a method of measuring whole-pack scrum force, the equipment used would not be practical for normal training purposes (for example, [PERSON] et al., [10], mounted a set of pads on a wall and used a force plate at the players' feet to capture force). In addition to equipment limitations, a major gap in the research is the lack of reliability testing in scrum force production; in a systematic literature review [3], only one study was found that performed any kind of reliability testing, and that was as a small pilot prior to their main study [11]. Reliability is a crucial component of any fitness test that indicates how well a test produces the same result under similar conditions [12]. While testing force production in a scrum machine is still rare, especially outside of research, and is in a nascent stage of research [2,3], we can look to similar strength tests for guidance. Pushing against a scrum machine for testing force production has been, in the prior literature and in the presented studies below, an isometric force production task [2,3]. Thus, the two previously used tests that are the most similar to testing are an isometric squat (highly biomechanically specific to a scrum) and, to a slightly lesser extent, the isometric midthigh pull [13, 14, 15]. [PERSON] and colleagues [13] published a review summarizing the reliability of both the isometric midthigh pull and the isometric squat; they summarized that the isometric midthigh pull demonstrates good within- and between-session reliability, as indicated by intraclass correlation coefficients (ICC) \(\geq\) 0.92, for peak force among well-trained athletes in a wide variety of sports (the reviewed samples mostly consisted of Division 1 American collegiate-level athletes).