Ask any experienced manager what matters most in FPL and most will give the same answer: the captain. Your captain score is doubled, so over a season the armband is worth hundreds of points. Getting it right most weeks beats almost every other skill in the game.
Step one: fixtures first
Start with the fixture, not the player. A good attacker at home against a struggling defence is a better captain than a great attacker away at a title rival. Look at how many goals the opponent concedes, whether they are missing defenders, and whether the match is likely to be open or tight. The fixture sets the ceiling.
Step two: form, but recent form
Form matters, but only recent form. What a player did two months ago tells you little; what he has done in the last four or five matches tells you a lot. Look for attacking involvement - shots, chances created, touches in the box - not just goals, because goals are noisy and involvement is stable.
Step three: certainty of minutes
A captain who does not start scores you nothing doubled, which is to say nothing. Players returning from injury, players in rotation-heavy squads, and players facing a congested fixture list all carry minutes risk. When two captain options are close, pick the one you are sure will play the full match.
The safety-first rule
Most weeks, the popular captain is popular for a reason. Going against the crowd with a differential captain can win a week, but it can also lose one badly, and over a season the safe pick usually wins. Save the bold captain for weeks when you genuinely need to make up ground, not for weeks when you are already ahead.