Going "over the top" wasn't a strategy; at the very most it was tactics. In reality, to arrive at point B one must leave point A, and in the case of attacking an enemy position on the Western Front in WWI, that would mean leaving the trenches. Typically soldiers would just climb over the parapet, but this did not always need to be at the opening of an attack. Of 80 British battalions that attacked on July 1st, 1916, just over 50 had already made their way into no-man's land before 0730, when the attack officially began. When they advanced, most troops that day did so behind a creeping barrage, though the rate and effectiveness varied greatly. Smoke or Gas, or both, could be used to obscure and prepare an advance, and machine gun barrages became a recurring element as the campaign wore on. So-called 'Russian Saps,' shallow or semi-submerged tunnels running under or into no-man's land, could also be used to aid the advance, as for example in the beginning of the Russian Brusilov Offensive in June 1916.