For all his military genius, intellectual capacity, administrative ability and plain hard work, Andrew Roberts notes (in Napoleon: A Life), we should not underestimate the part that sheer good luck played in Napoleon’s career:
In May 1800 there was a gap in the weather for crossing the Alps, and in June the rains slowed Desaix’s march away from Marengo enough so that he could return to the battlefield in time to save his commander-in-chief. In 1792 Colonel Maillard’s report on the events in Ajaccio was swamped under war ministry paperwork on the outbreak of war; in 1793 the pike-thrust at Toulon didn’t go septic; in 1797 Quasdonovich’s ammunition wagon received a direct hit at Rivoli, as Melas’s did at Marengo; in 1799 the Muiron had perfect winds on leaving Alexandria; the same year Sieyès’ other choices for the Brumaire coup were unavailable, and Kléber’s report on the Egyptian campaign didn’t arrive in Paris before the coup, during which Thomé’s sleeve was torn enough to anger his comrades.
Napoleon recognized this, and spoke more than once of ‘the goddess Fortune’. Later in his career he would believe that the goddess was spurning him, but for now he was persuaded that she was on his side.