With rapid progress in scientific research activities and growing competition for funding resources, it becomes critical to effectively evaluate an individual researcher's annual academic performance, or their cumulative performance within the last 3-5 years. It is particularly important for young independent investigators, and is also useful for funding agencies when determining the productivity and quality of grant awardees. As the funding becomes increasingly limited, having an unbiased method of measuring recent performance of an individual scientist is clearly needed. Here I propose the Z factor, a new and useful way to measure recent academic performance.