The importance of L2 writing development has continued to generate ongoing interest as evidenced by numerous publications over the past few decades (Fogal & Verspoor, 2020; Larsen-Freeman, 2006; Wolfe-Quintero, Inagaki & Kim, 1998). However, very little of this research has focused on the effect of specific practice tasks on learners’ development in the classroom. The presenters will share the results of a mixed-methods study investigating the effects of different types of writing practice on the development of complexity, accuracy, and fluency (CAF) in the writing of Japanese university students. Three groups who received regular practice in either sentence-combining, translation, or timed writing were compared on measures of CAF across one semester. The researchers will focus particularly on the results of the timed-writing group, who made significant gains across time and compared to other groups in the study on the measure of fluency. Furthermore, qualitative data will be shared illuminating why timed-writing was a more engaging task for learners as well as the strategies learners employed while performing the task. The findings from the study will be discussed in terms of pedagogical implications for L2 writing instructors.