Sentence:  As anyone who has ever maintained a baseball or softball diamond would agree, the pitcher's mound and batter's <WSD>box</WSD> present a special challenge. ... Batters dig in at the plate, disturbing the soil and making a hole that base runners must slide across when they approach the plate. To withstand the special stresses on these areas, only clay-based soils provide the necessary soil strength. ... [S]ome manufacturers have introduced clay-based soil products for pitcher's mounds and batter's <WSD>boxes</WSD>. These products include additives with special binding properties and are specifically designed to resist the stresses applied by the cleats of pitchers and batters. 
Meaning of the word marked with <WSD> tags:  The rectangle in which the batter stands.