This paper presents a replication and extension of Chi's (1978) classic study on chess expertise. A major outcome of Chi's research was that although adult novices had a better memory span than child experts, the children showed better memory for chess positions than the adults. The major goal of this study was to explore the effects of the following task characteristics on memory performance: (1) Familiarity with the constellation of chess pieces (i.e., meaningful versus random positions) and (2) familiarity with both the geometrical structure of the board and the form and color of chess pieces. The tasks presented to the four groups of subjects (i.e., child experts and novices, adult experts and novices) included memory for meaningful and random chess positions as well as memory for the location of wooden pieces of different forms on a board geometrically structured by circles, triangles, rhombuses, etc. (control task 1). Further, a digit span memory task was given (control task 2). The major assumption was that the superiority of experts should be greatest for the meaningful chess positions, somewhat reduced but still significant for the random positions, and nonsignificant for the board control task. Only age effects were expected for the digit span task. The results conformed to this pattern, showing that each type of knowledge contributed to the experts' superior memory span for chess positions.