The ability of estimation of situations has for safety reasons high relevance in mountaineering, whereby it is suggested, that alpine skills correlate with the ability of self-estimation. This yields to the aim of the study to elucidate the relationship between self-estimation and course time for the largest ski mountaineering race of the West Alps Patrouille des Glaciers (PdG). Therefore, 551 patrols of the original race from Zermatt-Arolla-Verbier and 749 of the Arolla-Verbier race in 2018 were analyzed concerning the relationship between estimated course time and effective course time. In average, the participants overestimated the effective course time about half an hour yielding to an underestimation of own's ski mountaineering capabilities. Furthermore, it was identified, that the better the performance of a patrol, the more likely an underestimation of own capabilities was detected. In addition, relatively clear indications were found that with increasing performance levels a better ability to assess ski mountaineering performance exists.