#811 · Graph setup: one Settings view, a tab for each type
Round 1. Every graph is set up in one place: its own overlay, opened from a new graph icon beside Settings' cog. There's a tab for each type (Scatter charts, Radars, Dials, Donuts), and each tab lists that type's graphs, edits the one picked, and previews it. The Charts, Radar axes and Pizza dials tabs leave Settings. It's built on #810's structure, and every graph listed is one #810 seeded, placed where it shows today.
Real data: Man Utd's 25/26 to December and the December Premier League capture, the same export as the #810 inventory. The previews are worked out live by the app's rules (the minutes bar, the league peer groups, the evidence floor, the save split's shares). Edits change the preview as you make them. Nothing is saved: reloading puts everything back.
Decisions, with my recommendation
Where it lives. Its own overlay on a graph icon beside the cog, called Graphs. Or a Graphs tab inside Settings? I'd keep it apart: Settings is about columns and roles, and #815's "Add new" wants somewhere to land that's only about graphs.
List, editor and preview side by side, the preview being #813's. Radars, dials and donuts have had no preview until now.
Where a graph shows: one tick per tab, grouped by view. Only the tabs that can draw that type are offered. The rest show greyed with the reason on hover. "new" marks a place nothing draws that type on yet (#812 and #738 build those): scatters on the card's two comparison tabs (your #667 idea), Player evolution's trail and League comparison.
Built-in graphs can be edited, with Reset to put them back, the way the radar and dial boards already work. Scatter charts are locked today, and that's the odd one out. They can't be deleted: taking every tick off hides one. Contracts & terms' two charts stay fixed, so you can place them but not edit them.
A scatter's axes: pick where each comes from, then the column. An attribute against a metric is allowed (that's what a pairing is). Two metrics still have to share a category, since the metric read is per category.
"Measured among" defenders, midfielders and attackers, from the pairings, offered on every scatter drawn for outfield players.
A new graph starts on the obvious place: a scatter on Squad comparison → Statistics & metrics, a radar on the card's Attributes, a dial on the card's League comparison, and a donut on the card's Statistics & metrics. #815 overrides this with the place you came from.