Defect precision provides information on how many defects a given software application appears to have. Existing approaches are usually based on time consuming model-based techniques. A viable alternative is the previously presented Abacus algorithm, which is based on Bayesian fault diagnosis.This paper presents a novel alternative approach - coined End that uses the same input and produces the same output as the Abacus algorithm, but is considerably more time ecient. An experiment was conducted to compare both the accuracy and performance of these two algorithms. The End algorithm presented the same accuracy as the Abacus algorithm, but outperformed it in the majority of executions.