Drum and bass 2-step — the standard DnB break at 170-plus: kick on 1, snare on 2, kick on the and of 3, snare on 4. The snares are the backbeat; the second kick is displaced by an eighth, which is the "2-step" and the whole reason the beat rolls instead of marching. Bar 2 adds a kick on the a of 4 as a pickup.
How it sits: hats play straight eighths (open on the and of 4 in bar 2) with quiet rim ghosts on the a of 2 and the e of 4, the leftovers of the sampled break this pattern descends from. The bass is a long sub: root held through beat 3, re-struck with the displaced kick, then a short move to the third or seventh on the and of 4. One chord, G minor — DnB bass is a drone, not a progression.
Listen for how the half-time illusion appears at full speed: the snares on 2 and 4 sound like a backbeat at 86.
Practice: at 120 first; the displaced kick must land exactly between beats 3 and 4.