FPL differentials, properly explained

A differential is usually defined as a player owned by under 5% or 10% of managers globally. That definition is nearly useless to you.

What matters is whether the eight people in your mini-league own him. A player on 3% global ownership who happens to be in four of your rivals' squads is not a differential for you. A player on 40% ownership that none of your rivals have is.

Points from a player your rival also owns cancel out. They are noise in the gap between you. Only the players you own and they do not can actually move it.

So the value of a differential scales with how far behind you are. Level with someone? A differential is a coin flip you did not need to take. Forty points behind with six gameweeks left? It is the only thing that can close the gap in time.

Not by ownership alone, and not by upside alone. The right differential is the one with the best combination of expected points and low ownership among the specific people you are chasing.

Fixtures matter more here than usual, because you are buying a short burst of separation rather than a season-long hold.

Differentials lose more often than they win. That is what makes them differentials. The reason to take them anyway is that a strategy which loses slowly and reliably still loses — and copying the template when you are behind is exactly that strategy.