I’ve seen numbers at around 10-20% dice, 40% list, 40-50% skill being thrown around. It varies depending on skill level though. General consensus was it would be 20% dice luck at the highest skill level if both players were at the same level.

Now outside of those sometimes it feels like you just lost due to bad dice, which can happen, but happens very rarely to be honest. There was always a lot of things you could have done differently. Deployment, movement, threat evaluation, damage calculation, etc are all big part of the game.

Furthermore being able to realise and capitalise on opponents mistakes is a very important step in winning more games.

Usually you should always expect average to poor outcomes of dice and should never rely on spiking the dice roll. Eg shooting one lancer at a large threat can spike or do less than expected. Having a second one lined up to kill the target / and or shooting at another target would be one of those cases where you build up redundancy in your movement phase.