BUMP

rank positions connected across ordered periods. Needs: 3-8 competitors with a full rank (1..n) per period.

rankingchange-over-time

DL-01 AGRAW

Use when

rank order changes over time: who overtook whom
league-table stories where position, not value, is the message

Do not use when

values matter more than positions (CH-TIM-01)
more than 8 competitors (lines tangle)
two periods only (CH-TIM-05 slope)

See instead

the metric value itself is the story: CH-TIM-01
only two periods: CH-TIM-05

Alternatives

CH-TIM-01 (values matter more than positions)

Rules

rank 1 at the top; the y axis is position, never value
every series labeled at both ends with rank and name, never a legend
one highlight maximum, drawn last

Never do this

plotting values on the bump y axis
more than 8 series
legends
smoothed curves between periods

QA before delivering

ranks are full permutations per period
labels at both ends
highlight <= 1
source present

Data shape

title	action title naming the mover
source	bottom-left always
x	array of ordered period labels
series	array of {name, ranks: [1..n per period], highlight?}

Sample data (golden)

{
  "title": "Casta moved from third to first in two quarters",
  "eyebrow": "SUPPLIER RANKING",
  "source": "Source: supplier scorecards, Q4",
  "x": [
    "Q1",
    "Q2",
    "Q3",
    "Q4"
  ],
  "series": [
    {
      "name": "Alpha",
      "ranks": [
        1,
        1,
        2,
        3
      ]
    },
    {
      "name": "Bravo",
      "ranks": [
        2,
        3,
        3,
        2
      ]
    },
    {
      "name": "Casta",
      "ranks": [
        3,
        2,
        1,
        1
      ],
      "highlight": true
    },
    {
      "name": "Delta",
      "ranks": [
        4,
        5,
        4,
        5
      ]
    },
    {
      "name": "Echo",
      "ranks": [
        5,
        4,
        5,
        4
      ]
    }
  ]
}