Abstract: A device for training batters to properly shift weight to the back leg at the beginning of a swing and to shift weight to the front leg during a swing when striking the ball in baseball and similar games. The device includes a first strap for fastening to the leading leg just above the knee and a second strap for fastening to the leading wrist, "leading" being the side towards a pitcher. An elongated member connects the two straps and comprises an elastic portion and an adjustable length portion, which includes a separable buckle so that the elongated member can be separated without removing either strap. In use, straps are emplaced on the knee and wrist and the adjustable length portion is adjusted to be taut but not stretched with the batter in the "ready" position. At the start of a swing, the hands move back, stretching the elongated member to encourage weight movement to the back leg.