Correlation between the GRAVITY fringe tracker residuals and the P_5%/P_95% injection stability metric, comparing STRAP and NAOMI. With NAOMI, the fringe tracking residuals tend to stay in the 80 nm–150 nm range because the P_5%/P_95% >  0.5 injection stability is high. This figure does not include 20% of the open-dome nights with wind speeds higher than 9 m s⁻¹, where telescope vibrations affect fringe tracking residuals (Woillez et al. 2016).