The first big swing element on bar and parallel bars: one precisely timed counter-movement takes you from the swing below the bar into support — timing, not arm strength.
The kip is the gateway to bar work: without it you never get from the swing below the bar up into support, and nearly everything beyond that stays locked. Which is exactly why it gets trained the wrong way — as a strength problem. Try to haul yourself up with your arms and you won't rise, however many pull-ups you own. The kip lives on a counter-movement: shoulders forward, feet back, at exactly the same instant. Drill the three grips first — overgrip, undergrip and the rotated el-grip — plus the regrip, standing on the floor, so your hand isn't searching mid-swing. And expect months rather than weeks: the bottleneck is timing, not strength. Once you accept that, you stop pulling harder and start experimenting with pulling earlier or later.