Susie has practiced several different strokes all summer, breast-stroke, back stroke, free style and butterfly, and mastered each one fully. she is very athletic and fit. sally chose to concentrate on only one style this summer, the breast-stroke. she had much more practice with this style than susie, but did not reach the criteria of mastery. susie is an average swimmer but works hard at practice. predict which girl is most likely to retain their breast stroke performance next summer.