Investigating the experiences of Major League Baseball (MLB) umpires, who epitomize professional nomadism, reveals how travel affects cognitive performance in more complex ways than the existing literature suggests. Specifically, our results indicate that traversing one, two, or three time zones—either east or west—does not significantly influence cognitive performance beyond what is experienced when traveling within the same time zone. However, the real value of our analysis is that it explains the contingencies that impact our core discoveries. Age is a key determinant in how travel impacts cognitive performance following transmeridian travel, especially when considering the length of stay at the destination. Older umpires appear to maintain their mental acuity in the initial days of an assignment after crossing multiple time zones but find it harder to sustain cognitive performance the longer they remain at the destination. Older umpires perform maximally in high-stakes games, suggesting they draw from their extensive experience navigating professional challenges throughout their careers. This observation indicates that seasoned professionals should be deployed to conduct crucial high-stakes tasks in person. However, our findings also highlight the importance of the scheduling of such tasks after travel events.