Ok so each little dot is a note I hit while playing a map in osu!mania. There are at least 10,000 notes across 50 maps plotted here. The higher the point the later the timing is, the lower the point the earlier the timing is. Going to the left, the spacing between notes gets smaller, and going right the spacing gets larger. As you can see my hits start to get all over the place as the spacing between notes get smaller. There is also a visible shift trending toward hitting late.
The yellow line represents the center of those points plotted, and the shaded area roughly contains 68% of points (a nice way to visualize UR). You can also see the points create these vertical bands, that's because no notes end up being spaced as such. Common bpms + 1/1, 1/2, 1/4 meters being common will do that.